A bomb blast on a passenger coach in northwest Pakistan on Thursday killed at least seven people and wounded another six, police said.

A bomb blast on a passenger coach in northwest Pakistan on Thursday killed at least seven people and wounded another six, police said.

The bomb was planted beneath a passenger seat and exploded in the outskirts of Peshawar, the region's main city, while the bus was en route to the town of Hangu.

"At least seven people have been killed and six wounded, the bomb was planted under a seat," senior police official Najeeb Ur Rehman told AFP.

Syed Jameel Shah, a spokesman for Peshawar's main Lady Reading Hospital, confirmed the death toll.

Peshawar is the gateway to the seven semi-autonomous tribal regions where the military has been battling Islamist militants for more than a decade.

The army launched a major operation in June to destroy bases of the Taliban and other militants in the North Waziristan tribal area.

It says has killed more than a thousand militants and lost 86 soldiers since the start of the current operation.