Chairman of the Afghan High Peace Council Burhanuddin Rabbani was killed Tuesday evening in an explosion at his house in Kabul, according to local TV channel Tolo.
Tolo said at least five more people were also killed and several others injured in the suicide attack that occurred inside Rabbani's house.
Some people were killed including Rabbani and some others including Massum Stanikzai, head of the joint secretariat of the High Peace Council, were injured, Tolo quoted an Interior Ministry source as saying.
Rabbani was meeting with a small group of Taliban who came to Kabul to meet peace council officials when the blast happened, a close source from the Rabbani office told Xinhua.
However, it was not immediately clear if the visiting Taliban members were involved in the attack.
One police officer on the spot told Xinhua that Rabbani was feared to have been killed.
However, one witness, a neighbor of Rabbani, told the Xinhua reporter on the spot that "the blast happened inside Rabbani's house, and many people injured including Rabbani."
Another witness told Xinhua, "It was a suicide bombing."
"The suicide bomb went off at 18:10 local time (1340 GMT) outside the house. There are casualties, but details will be released later," Hashmat Stanikzai, the provincial police spokesperson of Kabul said.
The security around was beefed up as many Afghan National Security Force units rushed to the site.
Rabbani, an aged former Mujahdeen leader and the former president of Afghanistan , was selected by President Hamid Karzai as chairman of the High Peace Council in October 2010.
The 70-member council was set up in October 2010 by President Karzai to broker peace with the Taliban insurgents.
However, the insurgent group repeatedly rejected the High Peace Council as a trick to deceive public opinion and called for the withdrawal of foreign troops from Afghanistan.
The Taliban launched in May this year a spring offensive against Afghan and NATO forces.
The outfit has also warned the civilians to stay away from official gatherings, military convoys and centers regarded as the legitimate targets by militants.
The Taliban also warned to target high-ranking Afghan officials including members of the peace council.