PESHAWAR, Pakistan (AFP) - Six children were killed and one injured on Sunday while playing with a hand grenade in north-west Pakistan, officials said.

The children, aged seven to 12, were playing near their house in the town of Hangu when the grenade exploded, local police chief Iftikhar Ahmed told AFP.

"Five boys and one girl were killed in the blast. One other child was injured," he said.

Mr Syed Ahmed Jan, a senior local administration official, added: "The children were playing with a hand grenade they found on nearby open ground."

Another police official said the children were all members of the same family who had migrated from the neighbouring Orakzai tribal agency where the military is battling the Taleban.

Hangu itself is regularly targeted by militants. A Pakistani schoolboy from a nearby village sacrificed his life to stop a suicide bomber, saving the lives of his classmates earlier this month.

The Pakistani Taleban have since 2007 waged a war against the state, intended to force the government to scrap its alliance with the United States and to impose the militants' brand of Islamic syariah law.