A teacher with the Fang Lin Elementary School, which was exploded on March 6 killing 41 children and teachers, said a black-clothed man broke into his classroom and lit a bag of explosives.

A local newspaper quoted the teacher, surnamed as Deng, as saying a man in black, with a bag in hand, approached him in the morning of March 6, while Deng's class of grade three pupils were on.

Deng told reporters that the man, in his 30s, looked ``suspicious''. When Deng told him to go, the man intruded and made his way into the classroom, putting down the bag and lighting a fuse to the explosives.

Deng said his instinct response was to call his students to flee. Following a big bombing, he felt down and lost consciousness.

The teacher said he thought the bag would have contained grain. If he knew it had explosives, he would have knocked him out.

Deng is now in a local hospital receiving medical care.

Local officials cannot confirm the teacher's claim. And, officers of China's Ministry of Public Security are now investigation the cause of the explosion.