Islamic State has claimed responsibility for a suicide attack that devastated a gathering of local elders in the eastern Afghan province of Nangarhar.
Afghan officials said four people were killed and seven wounded in the attack on Monday, while a statement from Islamic State said 15 "apostates" were killed and 25 wounded.
Attaullah Khogyani, spokesman for the governor of Nangarhar which is the main stronghold of Islamic State in Afghanistan, said the meeting of elders had been called to settle a dispute between local people when the bomber staged his attack.
Councils of tribal elders are a fundamental means of managing affairs in many parts of Afghanistan where government control is weak but they have been targeted by Islamic State as it seeks to establish its own authority in eastern Afghanistan.
The militant group, which in Afghanistan is based mainly in Nangarhar, issued a picture of the suicide bomber and said he had opened fire on the gathering before detonating his explosive belt, an account corroborated by survivors.
Afghan President Ashraf Ghani issued a statement condemning the attack.