Brad Pitt and Matt Damon Photo by: Sean Gallup / Getty
Fire Forces Matt, Brad from London Hotel | Brad Pitt
Matt Damon and Brad Pitt were forced to flee London's posh Claridge's hotel after a fire broke out Thursday morning, PEOPLE's London bureau reports.

According to a fire brigade source, more than 1,300 people – including Pitt, Damon and their Ocean's Twelve producer, Jerry Weintraub – vacated Claridge's, in Mayfair, when the alarm went off just before 11 a.m.

Besides the Ocean's men, guests Mick Jagger and Jim Carrey reportedly were also forced to leave the hotel.

The fire, which was small and apparently started inside some ducts in the hotel restaurant run by celebrity chef Gordon Ramsay, "meant that all guests and staff throughout the building were immediately evacuated," says a spokeswoman for Warner Bros., the studio behind Ocean's Twelve. She added: "As a result of this unfortunate incident, the Ocean's Twelve press conference and junket has had to be canceled."

Pitt and Damon are in the U.K. to promote the European release of their heist caper, which opens overseas in early February. Carrey and Meryl Streep are in town for Thursday's West End premiere of Lemony Snicket's A Series of Unfortunate Events.

As for the blaze, more than 30 firefighters on six fire engines raced to the scene and found ventilation ducting damaged. "There was heavy smoke on the ground floor and basement," says London Fire Service spokeswoman Corinne Gladstone.