Authorities have stepped up security after the FBI’s Joint Terrorism Task Force learned of a specific but “uncorroborated” terrorist threat to detonate a device at the Metro Red Line’s Universal City station today, law enforcement officials said Monday evening.

“The threat is imminent as it’s related to tomorrow (Tuesday),” Los Angeles Police Department Chief Charlie Beck said at a hastily called news conference at the Wilshire Federal Building in Westwood. “It’s very specific as was stated, the Red Line at the Universal City station off-ramp there, but the credibility still needs to be vetted out.”

Laura Eimiller, an FBI spokeswoman, said after the news conference that their international partners were made aware of the threat by a male caller in an unidentified foreign country who “stated that the attacker would detonate something at the station.”

Beck said the public may notice additional resources and safety measures on rapid transit today “out of an abundance of caution” because law enforcement officials did not have time to vet the threat in the way they would have liked.

“This one, we had to move quickly on,” he said.

Deirdre Fike, assistant director of the FBI’s L.A. field office, said the information was relayed Monday morning by their international partners to the Joint Terrorism Task Force. After the anonymous phone call was made on a public safety hotline, the task force immediately contacted its partners in Los Angeles so they could provide resources and a response to the threat, she said.

“Because of the specificity and the imminence of the threat, we felt it was important that we provide this information to the public,” Fike said.

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The threat came to light a few days after the one year anniversary of the Dec. 2, 2015, terror attack in San Bernardino that killed 14 people and injured 22 others at the Inland Regional Center.

Law enforcement officials are taking “all appropriate action” to address the threat and will continue to work throughout Monday night and today to determine its credibility and what response is needed, Fike said.

The Los Angeles County Metropolitan Transportation Authority said in a statement that it has beefed up its security presence across the entire Metro system and is taking a number of precautions.

“At this point, we don’t know if this is a credible threat, but the safety of our passengers, employees and the public is our No. 1 priority, so we take this threat very seriously,” Metro CEO Phillip A. Washington said in the statement.

At the news conference, Los Angeles Mayor Eric Garcetti encouraged people to “go about their normal day” today, adding that he will be visiting the Universal City station and boarding the Red Line himself in the morning.

But he and other officials also urged people to remain vigilant, take precautions, and report anything suspicious by calling 1-877-A-Threat or by using the iWatch app on a cellphone.

“When someone says they want to cause harm to Angelenos, we pull together and make sure that that is nothing more than a threat,” he said.

Los Angeles County Sheriff Jim McDonnell said the public will see an increased uniform presence, especially at transit stations, and canine explosive detection teams. There will be undercover operations underway as well, he said.

The department, along with its partners, also has the ability to pull together special weapons, bomb squad and hazardous material teams, he added.

The Sheriff’s Department and other local agencies have also been briefed to be “extra vigilant, especially around any critical infrastructure sites,” he said.

Eimiller said this type of threat isn’t an uncommon occurrence for the FBI.

“Unfortunately, we receive threats of this nature pretty regularly,” she said, adding that it’s “ultimately a judgement call” whether or not to inform the public.

Washington, of Metro, urged the public to report any suspicious activity as well. Passengers can call the Transit Watch Hotline at 888-950-7233 or notify them through their Transit Watch app.