A suicide bomber assassinated an Afghan peace envoy and former mujahedeen commander on Friday, in the latest blow to stuttering reconciliation efforts in the violence-wracked country.

Maulavi Mohammad Hashem Munib, the head of the government's High Peace Council in Kunar province, was killed along with his son and a bodyguard, the presidency said in a statement.

"He was on his way home from Friday prayers when he was attacked by a suicide attacker," provincial police chief Ewaz Mohammad Nazari told AFP.

One witness said that both Munib and the attacker had been torn to pieces, with body parts littering the scene.

Kunar, an eastern province bordering Pakistan, is a stronghold of the decade-long Taliban-led insurgency against President Hamid Karzai's government and its Western allies.

Karzai condemned the attack, saying that "the enemies of the people of Afghanistan have martyred one of the messengers of peace".

"The terrorists are trying to undermine the role of elders who are working for the good of Afghanistan, but they should realise that they can never achieve their evil goals by such heinous acts," he said.

The national head of the High Peace Council, former Afghan president Burhanuddin Rabbani, was assassinated last year by a purported Taliban envoy who hid a bomb in his turban.

Rabbani's murder -- Afghanistan's most high-profile political killing since a US-led invasion ousted the Taliban after the September 11, 2001 attacks -- was a major setback to Karzai's hopes of securing a deal with the militants.

As well as trying to negotiate with insurgents, the High Peace Council tries to reconcile them with offers of money and jobs.

But in a report last month the International Crisis Group questioned the organisation's "efficacy and legitimacy", citing "the predominance of mujahedeen and factional leaders" appointed to it.

Munib -- also a member of Afghanistan's Ulema Council, a government-funded Islamic authority -- was a former senior commander of Hezb-i Islami, one of the major Afghan mujahedeen groups that fought Soviet troops in the 1980s.

It is now sometimes regarded as the second-biggest insurgent organisation in Afghanistan after the Taliban, but Munib left it before Karzai took power and he had never taken up arms against the current government.

Mohammad Masoom Stanikzai, a senior official in the Peace Council, described Munib as an "influential figure", saying he had "drawn many insurgents to lay down arms and join the peace process" and blaming the Taliban for his death.

The Taliban could not immediately be reached for comment.

Progress towards peace negotiations in Afghanistan has been long, slow and complicated, with no sign that substantive talks are underway.

Kabul has said several times that it is in negotiations with the Taliban, who insisted in turn that they were only prepared to talk to representatives of the United States. Washington says the process should be Afghan-led.

NATO's US-led International Security Assistance Force has 130,000 troops in Afghanistan helping fight the insurgency and train Kabul's forces, but the bulk of them are due to be withdrawn by the end of 2014.

Analysts say there is a risk of the conflict deepening afterwards without a sustainable peace deal.

In its report, the Brussels-based ICG said the government's reconciliation programme "has taken on the look and feel of a large intelligence and mercenary operation aimed at establishing militias as a bulwark against the insurgency".

It added that it was "foundering in the wake of increased violence and targeted assassinations of leading political personalities".