By Jibran Ahmed
PESHAWAR, Pakistan (Reuters) - The chief financier of the Taliban-linked Haqqani network, one of the most feared groups fighting U.S.-led forces in Afghanistan, has been shot dead in the Pakistani capital Islamabad, militant sources told Reuters on Monday.
Nasiruddin Haqqani was a son of Jalaluddin Haqqani, a veteran guerrilla commander from southeast Afghanistan who rose to prominence battling occupying Soviet forces in the 1980s.
"Nasiruddin Haqqani was killed in Islamabad while travelling in a car with a few other unidentified people," one Taliban source told Reuters, adding that the attack took place on Sunday. "His body has been moved to North Waziristan."
It was not immediately clear who shot him or why.
Pakistani police and the government were not immediately available for comment.
Pakistan has been on high alert since a November 1 U.S. drone strike which killed Hakimullah Mehsud, head of the Pakistani Taliban.
Later on Monday, Nasiruddin's body was buried in the village of Danday Darpakhel - the same place where Mehsud died, Taliban sources said. It was unclear if the two events were related.
In June 2010, the United States Treasury designated Nasiruddin and two other Afghans as "specifically designated global terrorists" for their work as senior leaders and financiers for the Taliban and the affiliated Haqqani network.
The group is one of the main enemies of U.S.-led forces in Afghanistan, frequently launching attacks on foreign troops from mountainous hideouts in neighboring Pakistan.
Washington has long called on Islamabad to crack down on the group, long headed by Nasiruddin's father who was an ally of the United States during the rebellion against the Soviets.
The United States branded the Haqqani network, a group U.S. officials blame for high-profile attacks in Afghanistan, a terrorist organization in September 2012.
Nasiruddin was the elder brother of Sirajuddin, the guerrilla commander who now heads the Haqqani network and has directed some of the most brazen attacks against U.S. forces in Afghanistan.
Nasiruddin frequently travelled to the Gulf Arab states to raise money for the group, sources said.
"He was based in Rawalpindi (a city near Islamabad) along with his family for the past many years," said another senior Taliban commander close to the Haqqani network.
Nasiruddin Haqqani, also known as Doctor among Taliban fighters, was buried at 4 p.m. on Monday, he said. The region of North Waziristan, the stronghold of the Taliban insurgency, shares a border with Afghanistan.
Family members told Reuters they did not know who killed him. It was unclear if his death was linked to that of Mehsud, who was succeeded by hardline commander Mullah Fazlullah, who has vowed attacks across Pakistan to avenge the November 1 drone attack.
(Additional reporting by Mehreen Zahra-Malik and Saud Mehsud; Writing by Maria Golovnina; Editing by Andrew Roche)