The FBI has triggered a massive manhunt for six people -- four Chinese and two Iraqis -- who may pose a terrorist threat to the city of Boston, law enforcement officials briefed on the threat said today.
The six are suspected of having come into the United States from Mexico, and may have headed to New York and then to Boston, the target of a planned attack that could involve a lethal substance, possibly chemical or biological or explosive, three law enforcement officials briefed on the threat said.
The tip about the threat was given to the FBI by only one person, the officials said, and it had not been corroborated as of this afternoon.
"It's being worked aggressively and shared with our law enforcement partners,'' FBI spokeswoman Gail Marcinkewicz said.
The state Emergency Management Agency has partially activated its emergency response team, with representatives from the Department of Public Health, the Department of Environmental Protection, and the State Police monitoring the situation in the emergency bunker in Framingham until the threat has passed.
Meanwhile, the Associated Press is reporting that a federal law enforcement official has stressed the tip is one of many from around the country that routinely are forwarded to local task forces for further investigation. No credible, specific terror threat has been identified in connection with the tip about suspects possibly entering the country from Mexico.
The AP said the investigation prompted Gov. Mitt Romney, who was in Washington to attend Thursday's presidential inauguration, to return to Boston later Wednesday evening, his spokesman, Eric Fehrnstrom said. The governor planned to hold a news conference in Washington Wednesday night to discuss the matter before returning home.
FBI spokeswoman Marcinkiewicz said the terror alert had not been raised for Boston.
The AP also reported among the law enforcement agencies alerted was the Massachusetts Bay Transportation Authority, where Deputy Chief Paul MacMillan told the AP that an "alert bulletin" was issued to its officers, as well as subway, train, bus and station workers to be on the lookout for the individuals.
"There is no specific threat or target indicated," he said, declining to discuss the details further.