A militant leader, who openly challenged Pakistani Taliban commander Baitullah Mehsud, was killed in north-western Pakistan on Tuesday, media reports said.
Qari Zainuddin was fatally shot in his house in the town of Dera Ismail Khan, located near the lawless South Waziristan tribal district, the main stronghold of Mehsud.
Geo News television channel said the militant leader was killed allegedly by one of his supporters, who managed to escape after the incident.
No group immediately claimed responsibility for the assassination.
Zainuddin has recently accused Mehsud of pursuing a "foreign agenda" by waging an insurgency in his own country, and supported the military action against the warlord.
The government announced June 14 that the security forces had been told to carry out a decisive operation against Mehsud, who is blamed for dozens of terrorist attacks, including the suicide bombing that killed former prime minister Benazir Bhutto.
Pakistani jets have carried out multiple raids on suspected Taliban hideouts in South Waziristan over the week to soften up the militant targets.