San Francisco, Apr 22 (IANS): A shelter-in-place order at the University of California (UC), Berkeley, which lasted more than four hours as police investigated a "credible campus-wide threat", has been lifted.

"All clear - the situation has been resolved. Thank you for your patience," UC Berkeley police said on Twitter late Thursday, adding that based on investigation, it was "appropriate to end the shelter in place", reports Xinhua news agency

Police said the buildings would remain locked and in-person classes would be cancelled.

When UC Berkeley police issued the shelter-in-place order, people were asked to stay indoors and away from windows due to an unspecified emergency on campus.

In-person classes were cancelled and campus services were closed.

"Please leave the campus in a safe and orderly way via the closest route available," campus police tweeted.

The shelter-in-place order was issued at 9.30 a.m. on Thursday morning.

At 10.18 a.m., police said in a tweet that there was not an active shooter on campus, what they were searching for was a person "who may want to harm specific individuals".

It was unclear if police has found the person they had searched for.

In response to the threat at UC Berkeley, the Berkeley Unified School District temporarily placed eight of its schools on a soft lockdown, according to local media.

Late Thursday night, Chancellor Carol Christ issued a statement in which she said that regular i-person classes and campus operations will resume on Friday.