bomb threats US nationwide sandoval nr vpx_00000000.jpg
bomb threats US nationwide sandoval nr vpx_00000000.jpg
Now playing
01:29
Bomb threats reported across the US
AURORA, CO - DECEMBER 15: (EDITORIAL USE ONLY) Rocky Mountain Regional VA Medical Center investigational pharmacy technician Sara Berech holds a dose of the Johnson & Johnson COVID-19 vaccine before it is administered in a clinical trial on December 15, 2020 in Aurora, Colorado. The Johnson & Johnson vaccine could be submitted for emergency use by late January and is the only vaccine among leading candidates given as a single dose. (Photo by Michael Ciaglo/Getty Images)
PHOTO: Michael Ciaglo/Getty Images
AURORA, CO - DECEMBER 15: (EDITORIAL USE ONLY) Rocky Mountain Regional VA Medical Center investigational pharmacy technician Sara Berech holds a dose of the Johnson & Johnson COVID-19 vaccine before it is administered in a clinical trial on December 15, 2020 in Aurora, Colorado. The Johnson & Johnson vaccine could be submitted for emergency use by late January and is the only vaccine among leading candidates given as a single dose. (Photo by Michael Ciaglo/Getty Images)
Now playing
03:19
Doctor who voted to approve Johnson and Johhnson vaccine speaks out
Saudi Crown Prince Mohammed bin Salman attends a conference in the Saudi capital Riyadh on October 2018.
PHOTO: FAYEZ NURELDINE/AFP/Getty Images
Saudi Crown Prince Mohammed bin Salman attends a conference in the Saudi capital Riyadh on October 2018.
Now playing
02:10
US intel report: Saudi Crown Prince responsible for approving Khashoggi operation
PHOTO: CNN
Now playing
02:24
Acosta corrects CPAC organizer: Trump did lose the election
WASHINGTON, DC - JANUARY 17: The U.S. Capitol dome is seen beyond a security fence on January 17, 2021 in Washington, DC. After last week
PHOTO: Michael M. Santiago/Getty Images
WASHINGTON, DC - JANUARY 17: The U.S. Capitol dome is seen beyond a security fence on January 17, 2021 in Washington, DC. After last week's riots at the U.S. Capitol Building, the FBI has warned of additional threats in the nation's capital and in all 50 states. According to reports, as many as 25,000 National Guard soldiers will be guarding the city as preparations are made for the inauguration of Joe Biden as the 46th U.S. President. (Photo by Michael M. Santiago/Getty Images)
Now playing
02:33
This is what's in the $1.9 trillion coronavirus package
PHOTO: CNN
Now playing
09:36
I lost everything: Texas mom's devastating story from winter storm
Now playing
01:23
See what happened when CPAC organizers asked crowd to wear masks
The Pentagon, the headquarters of the US Department of Defense, located in Arlington County, across the Potomac River from Washington, DC is seen from the air January 24, 2017.  / AFP PHOTO / Daniel SLIM        (Photo credit should read DANIEL SLIM/AFP via Getty Images)
PHOTO: Daniel Slim/Getty Images
The Pentagon, the headquarters of the US Department of Defense, located in Arlington County, across the Potomac River from Washington, DC is seen from the air January 24, 2017. / AFP PHOTO / Daniel SLIM (Photo credit should read DANIEL SLIM/AFP via Getty Images)
Now playing
05:24
US carries out airstrikes on Iran-backed militia groups
A woman walks past mailboxes  seen outside of a US Post Office in Washington, DC on August 17, 2020. - The United States Postal Service is popularly known for delivering mail despite snow, rain or heat, but it faces a new foe in President Donald Trump. Ahead of the November 3 elections in which millions of voters are expected to cast ballots by mail due to the coronavirus, Trump has leveled an unprecedented attack at the USPS, opposing efforts to give the cash-strapped agency more money as part of a big new virus-related stimulus package, even as changes there have caused delays in mail delivery. (Photo by MANDEL NGAN / AFP) (Photo by MANDEL NGAN/AFP via Getty Images)
PHOTO: Mandel Ngan/AFP/Getty Images
A woman walks past mailboxes seen outside of a US Post Office in Washington, DC on August 17, 2020. - The United States Postal Service is popularly known for delivering mail despite snow, rain or heat, but it faces a new foe in President Donald Trump. Ahead of the November 3 elections in which millions of voters are expected to cast ballots by mail due to the coronavirus, Trump has leveled an unprecedented attack at the USPS, opposing efforts to give the cash-strapped agency more money as part of a big new virus-related stimulus package, even as changes there have caused delays in mail delivery. (Photo by MANDEL NGAN / AFP) (Photo by MANDEL NGAN/AFP via Getty Images)
Now playing
02:49
Biden announces 3 nominees to USPS board
PHOTO: CNN
Now playing
02:00
Weekend hindered by rain in the East and snow in the Northwest
The exterior of the U.S. Capitol building is seen at sunrise on February 8, 2021 in Washington, DC. The Senate is scheduled to begin the second impeachment trial of former U.S. President Donald J. Trump on February 9.
PHOTO: Sarah Silbiger/Getty Images
The exterior of the U.S. Capitol building is seen at sunrise on February 8, 2021 in Washington, DC. The Senate is scheduled to begin the second impeachment trial of former U.S. President Donald J. Trump on February 9.
Now playing
01:57
Senate parliamentarian rules against minimum wage increase in relief bill
Now playing
03:56
Marjorie Taylor Greene's challenger explains decision to run
Everyone wears masks and desks are spaced at the high school, where full in-person teaching has been offered since the school year began.
PHOTO: CNN
Everyone wears masks and desks are spaced at the high school, where full in-person teaching has been offered since the school year began.
Now playing
03:20
Ohio school is staying open with these safety measures
PHOTO: CNN
Now playing
03:44
Acting US Capitol Police chief explains 'operational challenges' from January 6 riot
Rep. Marie Newman (D-IL) speaks with CNN
PHOTO: CNN
Rep. Marie Newman (D-IL) speaks with CNN's Alisyn Camerota.
Now playing
07:17
Lawmaker reacts to Rep. Taylor Greene's tweet on her transgender daughter
An activist wears a "Fight For $15" T-shirt during a news conference prior to a vote on the Raise the Wage Act July 18, 2019 at the U.S. Capitol in Washington, DC. The legislation would raise the federal minimum wage from $7.25 to $15 by 2025.  (Photo by Alex Wong/Getty Images)
PHOTO: Alex Wong/Getty Images
An activist wears a "Fight For $15" T-shirt during a news conference prior to a vote on the Raise the Wage Act July 18, 2019 at the U.S. Capitol in Washington, DC. The legislation would raise the federal minimum wage from $7.25 to $15 by 2025. (Photo by Alex Wong/Getty Images)
Now playing
02:59
How to make sense of the minimum wage debate
AURORA, CO - DECEMBER 15: (EDITORIAL USE ONLY) Rocky Mountain Regional VA Medical Center investigational pharmacy technician Sara Berech prepares a dose of the Johnson & Johnson COVID-19 vaccine for a clinical trial on December 15, 2020 in Aurora, Colorado. The Johnson & Johnson vaccine could be submitted for emergency use by late January and is the only vaccine among leading candidates given as a single dose. (Photo by Michael Ciaglo/Getty Images)
PHOTO: Michael Ciaglo/Getty Images
AURORA, CO - DECEMBER 15: (EDITORIAL USE ONLY) Rocky Mountain Regional VA Medical Center investigational pharmacy technician Sara Berech prepares a dose of the Johnson & Johnson COVID-19 vaccine for a clinical trial on December 15, 2020 in Aurora, Colorado. The Johnson & Johnson vaccine could be submitted for emergency use by late January and is the only vaccine among leading candidates given as a single dose. (Photo by Michael Ciaglo/Getty Images)
Now playing
02:46
FDA says Johnson & Johnson vaccine is safe and effective
(CNN) —  

Dozens of businesses and institutions across the United States and Canada received email threats Thursday afternoon, prompting evacuations and sweeps of buildings.

Guy Dickinson tweeted this photo of  police at 17th Street and K Street Northwest in Washington, DC on Thursday afternoon.
PHOTO: Courtesy Guy Dickinson`
Guy Dickinson tweeted this photo of police at 17th Street and K Street Northwest in Washington, DC on Thursday afternoon.

At this time it’s unclear if the threats – which have been received in San Francisco, New York, Seattle, Miami, Washington, DC and other locations nationwide – are connected. The FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives said they are aware of the threats and are working with law enforcement to provide assistance.

“As always, we encourage the public to remain vigilant and to promptly report suspicious activities which could represent a threat to public safety,” the FBI said.

Email threats also have been received in Vancouver, Ottawa and Toronto, Canada.

Vancouver Police Department Sgt. Jason Robillard tells CNN that businesses have received threats. He is not aware of any buildings that have evacuated.

This email demanding $20,000 via Bitcoin was forwarded to CNN affiliate KOCO-TV in Oklahoma City by a viewer who received it at her business. It’s unclear whether everyone who received a threat on Thursday received the same email.

The message was identical to an email warning posted on social media by the Cedar Rapids, Iowa Police Department and similar to descriptions of other threats posted on social media nationwide.

The Cedar Rapids Police Department posted: “The Police Department has found NO CREDIBLE EVIDENCE that these emails are authentic. It appears to be a robo-email that has been sent throughout the area hoping to scam businesses out of money. We have also received information that businesses in surrounding counties may have also received this email.”

CNN is not disclosing the names of the sender and recipient or specifics of the Bitcoin account.

Similar threats were sent earlier

It is unclear if Thursday’s threats could be related to a series of hoax bomb threats that have been sent via an online messaging service to recipients in multiple states since late August.

CNN has learned that over more than three months, academic institutions, federal and state law enforcement agencies, gun stores, and municipal offices in more than a dozen states received threatening emails deemed hoaxes by law enforcement authorities.

In a warning reviewed by CNN, the FBI recently shared information with law enforcement authorities nationally about the prior emails sent by an email service called “Guerilla Mail.”

The bulletin indicated the FBI has not identified any real or hoax devices at the threatened locations, suggesting law enforcement deemed at least some of the threats credible enough to conduct searches.

Threats at universities, media, courthouse

In Seattle on Thursday, the University of Washington searched possibly affected buildings after receiving threats. It then noted in a campus-wide alert that the FBI had “advised that the email is not a credible threat.”

The Thurston County Courthouse in Olympia, Washington and the Park Record newspaper in Park City, Utah also received similarly threatening emails. People have been allowed back inside buildings at those locations, according to tweets on their verified Twitter accounts.

In California, the Riverside Sheriff’s Office had “an influx of email threats” and is taking them seriously, although no threat has been substantiated.

The San Francisco Police Department responded to reports of bomb threats at locations throughout the city.

“We have received information that several other cities across the United States have received similar threats,” police said.

Pennsylvania State Police are “investigating some bomb threats in the eastern part of the state,” a spokesman for the department told CNN.

University police later said the threat appears to be a hoax.

The Chicago Police Department received 15 to 20 reports of emailed threats in the past few hours, according to Officer Jennifer Bryk.

Director of Communications Anthony Guglielmi tweeted, “#ChicagoPolice are working with federal partners on the investigation, and at this time there is no elevated threat level for the city of Chicago.”

Threats were also emailed to the Charlotte News & Observer and the Raleigh News & Observer newspapers in North Carolina.

Dozens more threats continued to come in across the country later into the day, authorities reported.

CNN’s Jeremy Grisham and Hollie Silverman contributed to this report.