The Pakistani army said Sunday it is investigating reports that Pakistani Taliban leader Hakimullah Mehsud died from injuries sustained in a U.S. drone missile strike in mid-January.

The militant leader's death would be an important success for both Pakistan, which has been battling the Pakistani Taliban, and the U.S., which blames Mehsud for a recent deadly bombing against the CIA in Afghanistan.

The army's disclosure came shortly after Pakistani state television, citing unnamed "official sources," reported that Mehsud died in Orakzai, an area in Pakistan's northwest tribal region where he was reportedly being treated for his injuries.

"We have these reports coming to us," army spokesman Gen. Athar Abbas told The Associated Press. "We are investigating whether it is true or wrong."

Elder says funeral already held

A tribal elder told the AP that he attended Mehsud's funeral in the Mamuzai area of Orakzai on Thursday. He said Mehsud was buried in Mamuzai graveyard after he died at his in-laws' home. The elder spoke on condition of anonymity for fear of retribution from the Taliban.

Hakimullah Mehsud is seen in this Oct. 3, 2009 photo as he arrives to meet with reporters in the tribal area of South Waziristan along the Afghanistan border. (Ishtiaq Mehsud/Associated Press)

Pakistani intelligence officials have said that Mehsud was targeted in a U.S. drone strike in South Waziristan on Jan. 14, triggering rumours that he had been injured or killed. The strike targeted a meeting of militant commanders in the Shaktoi area of South Waziristan.

Mehsud issued two audiotapes after the strike denying the rumours. But Pakistani intelligence officials told the AP on Sunday that they have confirmation that the Taliban chief's legs and abdomen were wounded in the strike.

The officials spoke on condition of anonymity because they were not authorized to talk to the media.

Pakistani Taliban officials were not immediately available for comment, but low-level fighters have dismissed rumours of Mehsud's death in recent days as propaganda.

The drone strike that targeted Mehsud came about two weeks after a deadly suicide bombing he helped orchestrate killed seven CIA employees at a remote base across the border in Afghanistan. Mehsud appeared in a video issued after the bombing sitting beside the Jordanian man who carried out the attack.

The bomber, Humam Khalil Abu-Mulal al-Balawi, said he carried out the attack in retribution for the death of former Pakistani Taliban leader Baitullah Mehsud — Hakimullah Mehsud's predecessor — in a U.S. drone strike last August.

The U.S. refuses to talk about the covert CIA-run drone program in Pakistan but officials have said privately that the strikes have killed several senior Taliban and al-Qaida leaders.

Pakistani officials publicly protest the strikes as violations of the country's sovereignty, but U.S. officials say privately they support the program, especially when it targets militants like Mehsud who the government believes is a threat to the state.

Leader blamed for NATO convoy attacks

Mehsud, who has the reputation as a particularly ruthless militant, took over leadership of the Pakistani Taliban soon after Baitullah Mehsud's death.

The 28-year-old militant leader has focused most of his attacks against targets inside Pakistan, but his men have also been blamed for attacking U.S. and NATO supply convoys travelling through the country en route to Afghanistan.

Hakimullah Mehsud first appeared in public to journalists in November 2008, when he offered to take reporters in Orakzai on a ride in a U.S. Humvee taken from a supply truck headed to Afghanistan. He was the Pakistani Taliban's regional commander in the Orakzai, Khyber and Mohmand tribal areas before taking over the organization.

He has taken responsibility for a wave of brazen strikes inside Pakistan, including the bombing of the Pearl Continental hotel in the northwestern city of Peshawar last June and the attack on the Sri Lankan cricket team in Lahore earlier that year. There is a 50-million rupee ($633,000 Cdn) bounty on his head.

The Pakistani Taliban stepped up its attacks after the army invaded its stronghold of South Waziristan in mid-October. More than 600 people have been killed in attacks throughout the country since the ground offensive was launched.

Pakistani officials have said some of the militants have fled to neighbouring North Waziristan, an area dominated by groups launching cross-border attacks against U.S. and NATO troops in Afghanistan.

The army struck deals with the leaders of two of those groups, Gul Bahadur and Maulvi Nazir, before it invaded South Waziristan, promising not to target the militants if they stayed on the sidelines.

An umbrella group that includes the two militants and the Pakistani Taliban issued a pamphlet in North Waziristan on Sunday accusing the government of violating the agreement and warning it would trigger a major war if it launched any kind of military operation in the area.

The pamphlet issued by the Shura-e-Ittehad-ul-Mujahedeen, or Council of United Holy Warriors, said the government violated the agreement in various ways, including by creating a network of spies in North Waziristan who helped the U.S. kill militants in drone attacks.

"We have tolerated all sorts of mistreatment, but now we are not going to accept any kind of military operation in even our smallest area," said the pamphlet, a copy of which was obtained by the AP.

The Pakistani army has said it cannot launch another major operation for at least six months, but it has carried out two strikes in North Waziristan in the past two weeks.

"Westerners have some regard for civilians and they do distinguish between Taliban fighters and civilians, but the Pakistani army doesn't," said the pamphlet in a rare admission for a militant group. "Instead of the Taliban, it is bombing ordinary people's homes and their bazaars and killing innocent people."