The men were killed yesterday in Ladha area of South Waziristan tribal region which is controlled by the banned Tehrik-e-Taliban Pakistan.
Clashes between rival militant factions in the tribal areas have escalated following the reported killing of Mehsud in a US drone attack on August 5. Nazir is believed to have disputes with Taliban commander Baitullah.
However, Tehrik-e-Taliban Pakistan spokesman Azam Tariq told reporters his group had nothing to do with the incident. Some local residents said the attack could have been the work of Uzbek militants.
Maulvi Nazir had expelled Uzbek militants from the area dominated by his Ahmadzai Wazir tribe in 2007 after fierce clashes and Mehsud had provided them shelter.
Nazir's supporters were going from North Waziristan to Wana, the main town in South Waziristan, when they were attacked. Armed men who were hiding in bushes by the roadside began firing at them.
Among those killed was Miruddin, a close associate of Nazir. Some reports said Nazir's men were returning from Paktika province in Afghanistan, where they had gone to fight US-led coalition forces.
The militants were hoping to return to their homes after passing through the territory of the Mehsud tribe.
Nazir's group also denied reports that he was also killed in the attack. It said another rival militant commander, Turkistan Bhitani, was spreading "lies" about Nazir's death.
Meanwhile, 12 bodies of suspected militants were yesterday found in a private hospital run by the Taliban in Makeen area of South Waziristan after an air strike on a rebel hideout. The hospital was subsequently destroyed.
