Manila - Two boys were killed while playing with a hand grenade in their house in a northern Philippine province, a police report said Monday.

The cousins aged 9 and 13 died instantly after the grenade they were playing with exploded Sunday in their house in Bulacan province, 55 kilometres north of Manila.

Investigators said the grenade was owned by the father of one of the boys. It was unclear how the man, a farmer, acquired the grenade.

Illegal firearms and explosives are easily accessible in the Philippines despite regular crackdowns by law enforcement authorities. (dpa)