The attack is believed to have taken place on Sunday as Nasiruddin Haqqani, the group's financier and a son of its founder Jalaluddin, was travelling in a car with other unidentified people.

The Haqqani network is a key ally of the Afghan Taliban and has pledged allegiance to its leader, Mullah Omar, though it operates fairly independently.

A Taliban source told that Nasiruddin's body had been moved to North Waziristan, the stronghold of the insurgency, which shares a border with Afghanistan.

It is not clear who shot him or why. Nasiruddin Haqqani was on a US list of global terrorists.

The details of his death are still unclear, but reports say he was killed in a shooting incident in the city of Rawalpindi, next to Islamabad.

Pakistani police and government officials were not immediately available for comment.

Nasiruddin Haqqani was the elder brother of Sirajuddin Haqqani, the guerrilla commander who heads the Haqqani network.

The network is named after the brothers' father, Jalaluddin Haqqani, a veteran guerrilla commander from southeast Afghanistan who rose to prominence battling occupying Soviet forces in the 1980s.

RA/NJF