Bomb threats were made Tuesday afternoon against major hotels and office buildings housing U.S. banks in and near Tokyo, but the Metropolitan Police Department said it believes they were pranks.

The threats were received between 2 and 2:30 p.m. According to investigators, people who did not sound like native Japanese speakers said there would be explosions within 25 minutes. However, none were reported after the time had elapsed.

The buildings against which the threats were made in Tokyo and Kawasaki house U.S. and other foreign financial institutions, investigators said.