Pakistan: 3 children dies as mortar shell explodes

Three children were killed when an old mortar shell they were playing with exploded in Pakistan's restive northwest tribal region on Wednesday, police said.

The incident occurred in Matta Tehsil of Swat valley - once the stronghold of Pakistani Taliban militants.

The children were playing with the mortar shell in a field, unaware of it being a bomb when it went off injuring five of them, police said.

While three of the injured succumbed to their injuries in a hospital, two others are receiving treatment, police added.

The police said they have launched an investigation after collecting evidence from the site of the blast.