A part-time teacher at Waseda University has been arrested on suspicion of making more than 900 silent and nuisance phone calls to the secretariat of the school's president, police said Monday.

Yuichiro Ando, 37, made some 920 calls between mid-November and March, according to police, who are now looking into why Ando made the calls.

Waseda University public relations officials said Ando teaches Japanese history in the literature department.