Mohammad Haji Zaman denied claims he let Osama bin Laden escape
A suicide bomber has killed an influential Afghan tribal chief and 14 other people in eastern Nangarhar province, officials say.
Mohammad Haji Zaman was a powerful mujahideen warlord during the Afghan civil war in the 1990s.
He led tribal forces in the Tora Bora region during the 2001 US-led Afghan invasion but is suspected of allowing al-Qaeda chief Osama bin Laden to flee.
No-one has yet claimed responsibility for the attack.
Mohammad Haji Zaman - also known as Haji Zaman Gamsurek - was addressing a gathering of refugees in the Khogyani district of Nangarhar when the blast went off.
The bomber set off his explosives after approaching a group of tribal elders at the gathering, police official Col Abdul Ghafour told AFP news agency.
Mohammad Haji Zaman had been living in the north-western Pakistani city of Peshawar and had only recently returned to Afghanistan.
He always denied allegations that he allowed Osama bin Laden to escape from the Tora Bora mountains in 2001.
The BBC's Chris Morris in Kabul says that Nangarhar is a province that, under the guidance of local tribal leaders, had become more peaceful in recent months.
But it is on the border with Pakistan, an important target for militants wishing to smuggle arms.