Government and Taliban sources told RFE/RL's Radio Mashaal that a key commander in the Taliban-linked Haqqani network has been killed in a clash with security forces in Pakistan's South Waziristan tribal area.
Sources said fighting broke out when Farooq Zadran and 10 other Haqqani militants reached a security checkpoint in the restive region.
They said nine militants were arrested and one escaped.
The Haqqani network is an Islamist militant group operating on both sides of the Afghan-Pakistani border.
Zadran's brother Sangeen, the Haqqani network's chief commander in the Afghan provinces of Paktia and Paktika, was killed in September 2013 in a U.S. drone strike in North Waziristan.
He was replaced by another brother, Bilal Zadran, while Farooq Zadran became deputy commander.
U.S. officials have said the Haqqani network has ties to the government in Pakistan and have accused it of conducting high-profile attacks in Afghanistan.