MIRANSHAH (Pak): Up to 20 suspected militants were killed and several wounded on Tuesday in a blast at a training camp in a restive Pakistani tribal area bordering Afghanistan, officials said.

Local intelligence officials said the explosion happened at a bomb-making factory near Targakhel in the North Waziristan tribal district, a known hideout for Taliban and Al-Qaeda rebels.

"Our reports from local sources are that up to 20 people were killed," one official said on condition of anonymity.

Army spokesman Major General Waheed Arshad said that a 'group of some militants were making explosives and there was an explosion'. He was unable to confirm casualties.