BOSTON -- The Massachusetts Emergency Management Agency has been placed on standby, and public safety officials are meeting at the bunker, officials said Wednesday.

There have been reports that the FBI office in Boston received a call from an FBI office in California warning officials about a suspicious person that may be in the area. There have been no specific threats made, but FBI agents in Boston have been put on alert, and officials started to gather at MEMA at about 1:30 p.m.

Federal and state authorities are investigating a nuclear terrorist threat against Boston after a man calling from Mexico told California police that he smuggled two Iraqis and four Chinese over the border, the Boston Herald has learned.

“They got a call from across the border in Mexico to the California Highway Patrol and he said he brought two Iraqis and four Chineses (individuals)across the border and according to him, they stated soon to follow behind them would be some sort of material,” said a law enforcement source familiar with the investigation.

“He refers to some sort of nuclear material that will follow them through New York up into Boston.” According to the source, the caller has not identified himself and did not show up for a meeting with federal investigators in California but he did leave pictures of four Chinese men and some names at a “drop” site at the Mexico-California border.

“They were dropped by the source at a location. He literally threw them over a fence from Mexico to the U.S. side,” said the source. “There are pictures of the four Chinese and some names but just how accurate they are remains a question”...

A federal law enforcement official, speaking on condition of anonymity because the matter remains under investigation, told The Associated Press that the FBI's joint terrorism task force has not yet corroborated a tip that the suspects entered the United States through Mexico in recent days, possibly bound for Boston.

The official 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 investigation prompted Gov. Mitt Romney, who was in Washington to attend Thursday's presidential inauguration, to decided 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 Gail Marcinkiewicz said the terror alert had not been raised for Boston.

"Basically, what you have here is information that we often get," she said. "It's uncorroborated at this time."

"It's been passed on to our law enforcement partners and we're working it aggressively," she said.

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.

(Boston -AP, January 19, 2005) — Teams of police officers are prowling the streets of Boston with radiological sensors as the FBI tries to unravel uncorroborated information that indicates someone may intend to detonate a dirty bomb.

Eyewitness News is told every agency has been put on notice just in case.

ABC News says multiple sources confirm that the FBI is in possession of a detailed plan to smuggle nuclear material into the U.S. from Mexico through New York and into Boston.