07/18/2009 AT 6:00 PM ET
While police were investigating a bomb scare at the Four Seasons Hotel Los Angeles, actors Katherine Heigl and Gerard Butler, inside the hotel promoting their upcoming film, The Ugly Truth, were forced to evacuate, along with 400 other guests.
For two hours, the stars mingled with fans outside the luxury hotel before retreating to the nearby Il Cielo restaurant. Butler, one eye witness tells PEOPLE, was spotted posing for pictures with members of the AC Milan soccer team, in town to play the Los Angeles Galaxy Sunday night. Heigl, barely recognizable with her hair dyed brown, was seen leaving the hotel during the 1:45 p.m. evacuation.
Police investigated the premises and found no unattended packages or luggage and the hotel reopened two hours later. The bomb threat was delivered via telephone, police told PEOPLE.
Reporting by JOHNNY DODD