A performance of the Hasty Pudding Theatricals was interrupted last night and the theater evacuated after Harvard police received an anonymous phone call warning of a bomb.

Searches by the police and the Cambridge fire department turned up nothing, and sources said early this morning that Harvard police suspect at least two students of making the bomb threat.

The performance of the Pudding's show, A Forum Affair, was interrupted shortly before the end of the first act, according to Catherine W. Zipf '94, an official with the Pudding.

Five members of the Harvard Lampoon were escorted out of the theater shortly before the bomb threat, and sources indicated that at least two of these five students were suspects.

Harvard Police Sgt. William Donaldson said thatthe department's criminal investigation divisionwill attempt to determine who placed the call.

Donaldson noted that police had escorted thefive Lampoon members out of the hall. He would notconfirm or deny that those students were suspects.

Zipf said that final clubs and the Lampoon haverecently been playing jokes to initiate members.She said the Pudding were warned a couple of daysago that someone might try to play a trick duringa performance.

"We heard two or three days ago that there wasgoing to be a prank played," Zipf said. "We'reassuming this is it."

Lampoon officials could not be reached forcomment this morning.

Zipf said she was upset that the show wasinterrupted. After the fire and police departmentsearches, the second act began at 10 p.m.

"We really do regret that this happened. Theaudience was good and they seemed to be enjoyingthemselves," Zipf said. "We don't understand whywe were a target. It was unnecessary andmalicious.