A suicide attack has killed seven Pakistani soldiers in a restive northwestern tribal region near the Afghan border, Sky News reported on Monday.

The incident happened in North Waziristan, where the military has been fighting militants linked to the Taliban and Al-Qaeda since June last year.

"When being chased and cordoned, a terrorist exploded his suicide jacket. Resultantly, seven soldiers embraced shahadat (martyrdom)", the military said in a statement.

The overnight blast triggered a gun battle between militants and troops in which 19 insurgents were killed, the military said.