NEW HAVEN (AP) — A bomb threat forced the evacuation of several buildings at Yale University as well as nearby businesses in New Haven for hours on Friday, school and city officials said.

A single caller to the New Haven police non-emergency line indicated there were bombs in eight buildings on campus at about 2 p.m., police and school officials said. People in the buildings were initially told to go to the New Haven Green. Later, they were directed to certain indoor locations.

Yale gave the all clear at around 7 p.m. and said the campus had resumed normal operations.

Several city streets were blocked off as law enforcement officials with bomb-sniffing dogs prepared to search the buildings that were threatened. FBI and state police were helping Yale and New Haven authorities in the investigation and response.

“We’re treating this as if it is a legitimate threat, however at this time we are still working on who the caller was," said acting New Haven Police Chief Renee Dominguez at a late afternoon news conference.

Yale Police Chief Ronnell Higgins said the person who made the bomb threats did not give a reason why.

Yale spokesperson Karen Peart said the campus buildings that were threatened included Bingham Hall, Branford College, Grace Hopper College, Jonathan Edwards College, University Theatre, Vanderbilt Hall, Welch Hall and Yale Art Gallery. Bass Library and Saybrook College also was evacuated as a precaution.