Marine police (PPM) shot dead a man in his 20s, who was believed to have hurled a 'fish bomb' at them, yesterday.

District police chief, Supt Peter Anak Umbuas said in the 12.05 pm incident, six PPM personnel conducting a special operation around the waters of Nusa Kuya, Pulau Bumbum, noticed a suspicious looking pumpboat within 100 metres of them.

He said there were a man and two children in the boat.

"At a distance of about four metres, one of the personnel saw the man lighting up something and hurl a bottle-shaped object, believed to be a fish bomb, towards them but the object fell into the water and exploded.

"After that, the man hurled another similar object at the police boat but it also dropped and exploded in the sea," he said in a statement here today.

In defence, one of the personnel fired two shots, hitting the man.

Initial investigations found four glass bottles believed to contain ammonia, a detonator/fuse and about 10 kilogrammes of bombed fish in the pumpboat, he said.

Peter said police would continue to carry out operations to combat illegal fish bombing activities, which destructive to marine life.