NANJING - An explosion that killed one person and injured three others at an East China university on Tuesday was allegedly caused by workers attempting to steal lab materials, a university spokesman said on Wednesday.

The blast occurred at 9 am in a disused laboratory at the Nanjing University of Science and Technology in Nanjing, capital of Jiangsu province, destroying the lab and shattering windows in nearby homes.

It is thought to have happened while five workers were using a flame cutting machine to incise the gate of Lab 319, said Gong Zaichun, spokesman for the university, at a press conference.

The workers, hired by the university to demolish another lab, are suspected of attempting to steal the metal materials stored in Lab 319, Gong said.

Both labs were owned by the university's chemical industry college.

It remains unclear what material had triggered the explosion, and police are still investigating the case.