A senior Pakistani militant with $3 million U.S. bounty on his head has been killed along with three aides in neighbouring Afghanistan, three militant commanders and an intelligence official said on Monday.

Pakistani officials said the death of Abdul Wali, also known as Omar Khalid Khurasani, could deal a blow to nascent peace talks between Pakistan's Taliban, known as the Tehreek-e-Taliban Pakistan or TTP, and the Pakistani government after meetings facilitated by the Taliban rulers in Kabul.

Khurasani and his aides were killed in an explosion from an apparent roadside bomb while travelling in a car in southeastern province of Paktia on Sunday, the sources told Reuters on condition of anonymity. They did not say who they believed was behind the attack.

A fourth militant commander confirmed the death on Twitter: "He's no more with us," Ehsanullah Ehsan wrote in a tweet.

Khurasani was the chief of Jamat-ul-Ahrar (JuA), a TTP branch that is designated a terrorist group by the United Nations and United States, which had offered $3 million for information leading to his capture or death.

The reports of the death of a senior Pakistani Islamist militant in Afghanistan came just a week after the United States said it killed al Qaeda leader Ayman al-Zawahri in strike on a Kabul guest house.

Kabul's Taliban government and the Pakistani military and foreign office did not respond to requests for comment. The TTP said without confirming the death that it would release a detailed statement.

Khurasani's group had claimed responsibility for multiple attacks against police, military, minority Shiite Muslims and Christians, which killed hundreds of people in Pakistan.

For his strong anti-Shi'ite stance, Khurasani's group for some years had joined Islamic State group in Afghanistan and Pakistan before returning to the TTP's fold last year, officials say.

Among the other three militants killed along with him, one was Mufti Hasan, who has been described by Pakistani officials as a senior commander working for Islamic State.

Khurasani, once seen as hostile to any negotiations with the Pakistani government, was among TTP leaders who held a session of peace talks in Kabul with a delegation of religious scholars sent from Pakistan, Pakistani officials have said.

The TTP wants to overthrow the government in Pakistan and replace it with a harsh version of Sharia law.

(Writing and Additional reporting by Asif Shahzad in Islamabad; Editing by Peter Graff)