Asmatullah Shaheen, a Pakistan Taliban commander wanted by the government for ordering suicide bombings, has been shot dead in an attack which also killed three associates.
Shaheen, of the armed group Tehreek-e-Taliban Pakistan [TTP], was ambushed on Monday in Dargah Mandi village near Miransha, which is in North Waziristan.
"Unknown attackers opened fire on Asmatullah Shaheen's car. He along with three associates died on the spot," a security official in Miranshah told news agency AFP.
No group has yet claimed they carried out the attack. The Pakistan government had a 10m rupee - $95,000 - bounty on his head.
Shaheen was leader of the Bhittani tribe and also chairman of the TTP's supreme council for two years. He was appointed as interim chief of the TTP shortly after Hakeemullah Mehsud was killed in a US drone strike.
He said he ordered the suicide attack on a Shia procession in Karachi in December 2009, which killed at least 43 people and wounded more than 100.
He was also responsible for storming a paramilitary outpost in the northwestern district of Tank in 2011, killing one soldier during the fighting and kidnapping 15. The majority of the those kidnapped were later executed while the others escaped.