(CNN) -- Pakistani security forces killed 23 militants late Wednesday in a firefight in a thinly governed tribal area in the northwest of the country, military officials said.
Militants tried to ambush a convoy of security forces in North Waziristan as it returned from rescuing soldiers wounded by a suicide bombing earlier Wednesday, the military officials said.
Three members of the security forces were wounded in the fighting, they said, and a search operation was under way in the area.
North Waziristan is rife with militants and is the area where the United States conducts its most intensive campaign of controversial drone strikes against the Pakistani Taliban and al Qaeda operatives.
It wasn't immediately clear which group the militants killed Wednesday were from.