World Bulletin / News Desk

A gunman opened fire on students after walking into a high school in Potiskum in northeast Nigeria, critically injuring six, witnesses and a humanitarian aid worker said.   

In Friday's attack, the gunmen arrived in the early morning andopened fire at the gate of the business school, witnesses said. 

A suicide bomber died when he blew himself up prematurely in the car park of the College of Administrative and Business Studies in Potiskum, and security guards armed only with clubs ran away according to an anonymous security officer and a hospital worker. 

A second bomb exploded in the college dormitory but no one was injured.