LOS ANGELES >> The FBI and local law enforcement agencies say they have stepped up security on Los Angeles County’s commuter rail system after the FBI was informed a terrorist attack on the Universal City subway station was planned for Tuesday.

Although the threat’s credibility had not been confirmed, authorities were taking no chances, Deirdre Fike, assistant director of the FBI’s Los Angeles office, told reporters tonight. “Information was relayed this morning to the FBI’s Joint Terrorism Task Force from our international partners that there was a potential threat from an anonymous phone call that was made on a public safety line,” Fike said.

The caller was very specific, telling authorities the Los Angeles County Metropolitan Transportation Authority’s Universal City station was the target, she said.

“We are right now looking at the credibility of the threat,” Fike said.

Although authorities tend to receive more such threats during the holidays, she said, they chose to tell the public about this one because of its specificity and because the attack was threatened for the next day.

The Universal City Red Line station is adjacent to Universal CityWalk, an area filled with restaurants, nightclubs and other entertainment activities and often crowded with tourists. Universal Studios and several high-rise hotel and office buildings are nearby.

Los Angeles County Sheriff’s deputies could be seen patrolling the area with dogs tonight.

Mayor Eric Garcetti urged commuters to carry on with their normal activities Tuesday but to expect to see more security at every commuter rail stop in the region. “In fact I’ll be boarding the Red Line myself tomorrow morning at Universal City,” he said.

Police Chief Charlie Beck and Sheriff Jim McDonnell said stepped-up security would include additional uniformed officers, including some with dogs, as well as officers in plainclothes.

“This could be real, it could be a hoax. But we must remain calm but vigilant,” McDonnell said.

Both he and Beck encouraged anyone who sees anything suspicious to contact authorities immediately.