The shooter in Bulgaria's town of Lyaskovets has been rendered harmless and arrested after negotiations with psychologists.

Petko Petkov has been wounded and taken to hospital after barricading himself at home and holding his mother hostage for several hours, BGNES reports.

The 53 year old man shot dead a police officer Friday morning, and wounded 3 more. He is thought to be mentally ill, unemployed, and hasn't left his home since 2010.

He has been complaining from the children playing in the schoolyard and more than once has threatened to shoot at them.

The school principal has repeatedly informed the police about the threatening letters sent by Petkov and has warned the children to avoid playing in the yard and steer clear of Petkov's house.

Teachers at the school say the latest letter was from yesterday, while children claim he had threatened them in person.