At a time when their actions are under question in the fatal shooting of an airline passenger, federal air marshals will expand their work beyond airplanes, launching counterterror surveillance at trains stations and other mass transit facilities in a test program this week, according to a published report.

Teams of undercover air marshals and uniformed law enforcement officers will fan out to bus and train stations, ferries, and mass transit facilities across the country to “counter potential criminal terrorist activity in all modes of transportation,” The Washington Post reported on its Web site Tuesday night, quoting documents from the Transportation Security Administration.

The Post said documents showed the teams will take positions in public areas along Amtrak’s Northeast Corridor and Los Angeles rail lines; ferries in Washington state; and mass transit systems in Atlanta, Philadelphia and Baltimore. Teams will patrol the Washington Metro system, as well and will consist of two air marshals, one TSA bomb-sniffing-canine team, one or two transportation security inspectors, one local law enforcement officer, and one other TSA employee.

Federal officials said there is no new intelligence indicating that terrorists are interested in targeting transportation modes, the Post said.

Rather, the Transportation Security Administration is trying to expand the role of air marshals, who have been eager to conduct surveillance activities beyond the aircraft, and provide a beefed-up law enforcement presence at bus, train and other public transit stations over the busy holiday period.

“We think this is a very good approach to test our tools and quickly deploy resources in the event of a situation or a threat,” the Post quoted Federal Air Marshal Service spokesman David Adams as saying. “It shows we could be at any of these places.”

Some members of the team will be obvious to the traveling public and wear jackets bearing the TSA name on the back. Others will be plainclothes air marshals scanning the crowds for suspicious individuals. It is unclear how many viper teams will be on patrol through the New Year’s holiday, but air marshal officials confirm that they will be at seven locations across the country.

Although the department claims otherwise publicly, a confidential internal report within the Department of Homeland Security admits air marshals “overreacted” when they gunned down a Florida man at Miami International Airport last week.

The report, which may never be released publicly, confirms that preliminary interviews with witnesses conflict the statements of air marshals who claim Rigoberto Alpizar shouted he had a bomb as he stormed off a plane and up a jetway at the airport.

“Although witness statements contain conflicting information, none of those interrogated following the incident collaborate any utterance by the suspect that he either possessed, or intended to detonate, an explosive device,” the report says.