MIRAMSHAH, Feb 19 A son of veteran Afghan militant commander Jalaluddin Haqqani was killed in Thursday's US drone attack on a village in North Waziristan.

Official sources said here on Friday that Mohammad Haqqani, 22, was killed along with three other militants in the missile strike on a house and a vehicle in Derga Mendai, five kilometres west of Miramshah.

They said that Mohammad Haqqani was actively taking part in the Taliban fight against US-led Nato forces in Afghanistan and that he was in the area to attend a funeral when the US drone fired two missiles at his vehicle, killing him and his three associates.

His elder brother Siraj Haqqani is on the US list of most wanted militants.

Agencies add Jalaluddin Haqqani, believed to be in his 60s or older, is said to be too ill to do much now, and his son Siraj is running the network. The group is alleged to make its money through kidnappings, extortion and other crime in at least three eastern Afghan provinces.

US forces in Afghanistan describe Siraj as one of their biggest enemies and the US has posted a bounty of up to $5 million for him.It was not immediately known if Siraj was in the area at the time of the attack, and if he was, whether he was hit in the attack, security officials said.

A local commander of Pakistani Taliban in Mirali -- a town in North Waziristan -- confirmed that Mohammed Haqqani died in the missile attack with three of his associates on Thursday. A man from Haqqani's family said his funeral was held near Miramshah.

The strike at the heart of the Haqqani network comes close on the heels of a series of arrests that together are being seen as the most significant blows in years to insurgents.