(CNN) -- In the past week, U.S. officials have announced charges in five terrorism probes in five states. It is a confluence of cases unlike anything the country has seen since the September 11, 2001, attacks.
Najibullah Zazi, 24, has been indicted on a charge of conspiracy to use weapons of mass destruction in the U.S.
But CNN's national security analyst Peter Bergen and law enforcement analyst Mike Brooks say not to read too much into it -- the rush of arrests is a coincidence.
"These are things that are happening completely independently," Bergen said.
Brooks agreed, calling it a "happenstance."
Last weekend, authorities arrested three suspects -- two in Colorado and one in New York -- for allegedly lying to the FBI in a terrorism probe. One of the three is now also accused of plotting to make a powerful bomb.
A federal judge on Friday ordered Afghan native Najibullah Zazi, 24, of Colorado to remain in custody. Zazi is charged with plotting to set off "weapons of mass destruction" in the United States.
Investigators say Zazi plotted to make bombs from household chemicals. He made several recent purchases from beauty supply stores in suburban Denver, telling workers he had "a lot of girlfriends," employees said Thursday. Watch how Zazi was caught on tape »
Zazi's father, Mohammed Wali Zazi, 53, also from suburban Denver, and Ahmad Wais Afzali, 37, a Muslim cleric and funeral director from the New York borough of Queens, also have been charged with lying to federal agents in the case. Both have been released on bond.
On Thursday, officials announced an indictment against a resident of the New York City borough of Brooklyn for conspiracy to commit murder abroad and for support of foreign terrorists.
Betim Kaziu, 21, was indicted for conspiracy to commit murder abroad and support foreign terrorists. The U.S. attorney's office said he wanted to join the militant group Al-Shabaab in Somali and to "take up arms against perceived enemies of Islam."
In Texas, a 19-year-old Jordanian was arrested this week on suspicion of plotting to bomb a Dallas skyscraper.
Federal officials said Hosam Maher Husein Smadi, who entered the United States illegally and lived in Texas, tried to set off an explosive attached to a vehicle at the base of the 60-story Fountain Place office tower.
Meanwhile in Springfield, Illinois, an alleged would-be terrorist was arrested on charges of trying to detonate a truck bomb to blow up a federal building.
Justice Department officials said Michael Finton, also known as Talib Islam, 29, of Decatur, Illinois, drove a vehicle he believed contained a ton of explosives to the Paul Findley Federal Building and Courthouse in Springfield. He got out of the truck, got into a waiting car with an undercover agent, and then, when he was a few blocks away, attempted to detonate the bomb with a remote-control device.
And in North Carolina, three new charges were announced against a man who allegedly planned to attack the U.S. Marine base at Quantico, Virginia. Danield Patrick Boyd and seven others already had been charged with conspiracy to provide material support to terrorists and conspiracy to murder, kidnap, maim and injure people. They allegedly planned to attack the U.S. Marine base at Quantico, Virginia.
At any given time, FBI agents "are proactively looking at a lot of different things. And there are ongoing cases right now," Brooks said.
There was one element of the developments of the past week that was coordinated, Bergen and Brooks noted -- the timing with which authorities released information about the cases in Illinois and Texas.
Given the similarities between the two cases, authorities feared word of the Illinois arrest could tip off the Texas would-be bomber of an undercover sting operation, according to a federal law enforcement official familiar with the cases. So authorities withheld word of the Illinois arrest until the Texas sting operation was completed.
Do these various incidents suggest a spike in homegrown terrorism? "I think it's really too soon to tell," said Clark Kent Ervin, a CNN security analyst and former inspector general of the Office of Homeland Security.
It appears that the case involving suspects in New York and Denver and the Dallas case may have been planned for the anniversary of the September 11 attacks, Ervin said. "It just underscores that we remain under potential attack here."
It also shows that "every city in the United States, no matter how big or prominent, can be a potential terror target," he added. An attack in a place not generally thought of as a terrorist target "would arguably have a bigger psychological effect," he said.
While the five probes do not appear linked, they do involve suspects of a similar "socio-economic profile," said Bergen.
"The profiles of the people... generally speaking is much closer to what we see among European Muslims," he said. "They tend to be less well integrated" into mainstream society, and in many cases have faced economic difficulties and unemployment, Bergen said.
If there is a link among the suspects, Bergen said, "it's a feeling of exclusion from the American dream."