A mentally ill man committed suicide after shooting dead a policeman who was trying to negotiate an end to a family hostage drama at a house in Bangkok, early Sunday morning.

Police rushed to a building in DK Rama 2 housing estate on Rama II Road at 9.45pm on Saturday after being told that a deranged gunman was holding family members hostage there.

Pol Lt Col Kittichon Janyarom and his team approached the building to open negotiations.

Kittichon was shot three times in his chest and hand, and was later pronounced dead. One other policeman was slightly injured.

After the shooting, police rescued family members from the house, including a 15-year-old daughter who had been hit in the face with a gun.

A rescue worker said that last month that colleagues had sent the man to a mental health facility at the request of local police, and the man had threatened to hurt rescue workers at that time.

It was reported that the man had not been treated and had not taken his medications for a year.

Overnight, police told neighbours to stay indoors for their own safety while they were trying to calm the gunman down.

Police officers used a loudspeaker to talk with the man and gunshots were heard at times from the inside. 

The gunman, 49, was identified only as Boonma. He was found dead on a mezzanine.