LOS ANGELES, Nov. 11 (Xinhua) -- A bomb threat at the University of Southern California (USC), a leading private research university located in Los Angeles, caused an evacuation from multiple buildings of the university campus on Thursday, authorities said.

"Grace Ford Salvatori Hall, Sample Hall and Wallis Annenberg Hall are being evacuated due to a bomb threat," the university said in a tweet Thursday afternoon, urging people to stay away from the area.

According to the university's official Twitter account, the Los Angeles Police Department and the USC Department of Public Safety conducted a search in the area. About half an hour later, law enforcement agencies determined the evacuated buildings are safe and the related buildings were reopened.

"There are quite a few police cars here on campus while helicopters hovered in the sky," a USC student surnamed Li told Xinhua. He was at a rehearsal of a campus band and had to suspend practice to evacuate with his schoolmates.

"I saw people evacuate from the buildings immediately after receiving university notification, but not in panic mode," he added.

Multiple Ivy League schools in the East Coast of the U.S., including Yale, Columbia, Cornell and Brown, had also received bomb threats and were forced to warn students to evacuate campus buildings earlier this month. U.S. law enforcement agencies didn't deem any of the threats credible.