Md. Tunnel Threat Suspect Arrested

(CBS/AP)  Authorities have arrested a man they say may be connected to a threat that prompted the temporary shutdown of the Baltimore Harbor Tunnel and restrictions in another.

The suspect was one of four people arrested on immigration charges after several raids were conducted at businesses with Middle Eastern connections.

Authorities closed one of two highway tunnels carrying traffic under Baltimore's harbor for nearly two hours Tuesday and partially shut the other due to a phoned-in possible threat that vehicles full of explosives could be detonated inside the tubes.

The Baltimore Harbor Tunnel was closed and the Fort McHenry Tunnel was reduced to one lane of traffic in each direction, said Lt. Col. David Franklin of the Maryland Transportation Authority Police. The closures began about 11:30 a.m. and officers began reopening the tubes about 1:15 p.m.

CBS News correspondent Bob Orr reports that the FBI is questioning 30 people of Egyptian heritage who've been rounded up in the Baltimore area as part of the investigation.

Sources say that at least two weeks ago an Egyptian being held in the Netherlands told U.S. officials of a plot to use a vehicle bomb (or bombs) to attack "an unspecified tunnel in the Baltimore area," reports Orr.

While the FBI and Homeland Security officials played down any danger, saying they've found no evidence to corroborate the threat, Maryland state officials decided to restrict traffic and then shut down the two tunnels, Orr added.

The threat investigation isn't over, an official says, but the "prudent and proper thing" to do is to reopen the tunnels under Baltimore's Chesapeake Bay harbor, a transit official says.

Closing the tunnel for nearly three hours meant a significant disruption on the East Coast's major north-south highway, Interstate 95, which runs between Washington, Philadelphia and New York City.

"We received some information a couple of days ago with a possible threat to a tunnel, nothing specific. We are interviewing people as we speak," said Carla McIntosh, a spokeswoman for the FBI in Baltimore. She said she could not give details.

Jim Pettit, a spokesman for the governor's homeland security office, said: "We're acting out of an abundance of caution."

A federal law enforcement official, speaking on condition of anonymity, said the threat was phoned in to authorities by a person claiming to have information from abroad. Authorities are skeptical of the claim, but are checking it out nonetheless, the official said.

Even though authorities questioned the credibility of the threat, they were looking for several men in the Baltimore area who the source said would drive "explosives-laden vehicles" into the tunnel, said another federal law enforcement official, who also spoke on condition of anonymity.

The decision to close the tunnel was made by state and local, not federal, authorities, that official said.

An administration official told CBS News: "We believe the source is providing information based on the expectation that the source will receive special treatment for unrelated crimes committed overseas."

Orange dump trucks blocked the entrances to the tunnels, which carry Interstates 95 and 895 under water. As cars and trucks reached the heads of long lines, police officers directed them to detours.

"While the information was somewhat specific, to date the intelligence community has not found evidence that corroborates the information. This is an ongoing investigation," FBI special agent Richard Kolko said.

McLhinney said vehicles were stopped but he would not say what police were looking for. He did say nothing had been found as of early afternoon.