Annapolis, Maryland (CNN) -- A message found in at least one of two incendiary devices that were mailed to two Maryland state offices complained about homeland security road signs in the state, according to a government official with access to information on the investigation.
Two Maryland employees suffered slightly burned fingers when they opened packages containing devices that set off a flash of fire, smoke and a sulfur smell, authorities said.
The government official said an ABC News report on the note seemed accurate. According to ABC, the note read, "Report suspicious activity. Total Bulls..t. You have created a self-fulfilling prophecy."
The packages were sent through the mail to two state office buildings. One was addressed to Gov. Martin O'Malley, said Greg Shipley, a spokesman with Maryland State Police. The other was addressed to the Maryland Department of Transportation.
Based on the packages' destinations, the government official said he believes the person who wrote the message was referring to flashing road signs posted on some Maryland roads that urge drivers to report suspicious activity.
CNN spoke with law enforcement officials about the note. Maryland State Police did not have any information about the note.
Investigators have considerable forensic material to work with, the government official said. There was a return address on one of the packages, but it turned out to be bogus, the government official said.
A law enforcement official equated the incendiary devices to when "you have a lighter and combine it with a stream of hairspray and fire shoots out."
Maryland State Delegate James King told CNN there were no threats before Thursday's incidents.
One of the packages had holiday stamps, and both resembled the shape of a book, police said.
"There are a lot of questions yet to be answered," said Shipley, adding that numerous federal, state and local agencies are involved in the investigation.
Officials indicated they did not find explosive materials with the devices, which will be sent to an FBI laboratory in Quantico, Virginia, for detailed examination.
About 300 state employees were evacuated from the buildings.
A third package was being examined at the state Department of Health and Mental Hygiene because it matched the description of the other two, said spokesman David Paulson. The building was not evacuated.
Authorities responded to devices found in a state House office building in Annapolis and at the Maryland Department of Transportation headquarters near Hanover, said Philip McGowan, a spokesman for Annapolis Mayor Joshua Cohen. Hanover is southwest of Baltimore.
The Jeffrey Building, on Francis Street in Annapolis, received a package described as the size of a book and addressed to O'Malley, Maryland State Police said. When it was opened about 12:25 p.m. by a mail room employee, it "triggered a reaction involving smoke and a sulfur-like smell," state police said in a written statement.
The employee sustained minor burns to his fingers but refused further medical treatment, the statement said.
A robot examined the device, police said.
The building was evacuated for about two hours.
At about 12:45 p.m., another incident occurred in the Maryland Department of Transportation headquarters, state police said. "When an employee opened the package, a similar reaction to the Jeffrey building incident occurred."
The employee reported burned fingers and was taken to a hospital for an examination. Three others were taken to a hospital as a precaution, but they did not suffer physical injuries, officials said.
The 250 evacuated employees at that building were not back inside as of late Wednesday afternoon.
State officials stressed the devices did not cause widespread damage.
"This is not to be compared to a significant explosion that you think of when you say that word. I want to stress that," Shipley said.
Security precautions were being taken in other state buildings.
The Jeffrey Building in Annapolis houses the state Homeland Security, Secretary of State and Veterans Affairs offices, and some divisions of the governor's office, according to state property managers.
State House Speaker Michael E. Busch said mail service has been suspended in the legislative complex.
"While the investigation is ongoing, it appears that two incendiary devices were transported through state government mail rooms," Busch wrote in a statement. "We would encourage you to use reasonable caution in handling any packages that come to your office for the time being, and not open any mail until we have more complete information."
The Annapolis police bomb squad and firefighters responded, McGowan told CNN, as well as the FBI and the state bomb squad.
A Department of Homeland Security official said the department is closely monitoring the situation and is working with law enforcement agencies. Maryland State Police are taking the lead in the investigation.
CNN's Mike Ahlers, Jeanne Meserve, Barbara Starr, Tim McCaughan, Dugald McConnell, Carol Cratty, Brian Todd and Joshua Levs contributed to this report.