Atahullah Khogyani, a spokesman for Nangarhar province’s governor, said a boy set off his explosives inside the house of a pro-government militia commander in Pacheragam district.
Khogyani said 40 wounded men and women were rushed to hospital and local residents said 10 people were killed, Reuters reported.
Pro-government militias often work with overstretched Afghan security forces to prevent territories falling into the hands of the Taliban and Daesh (ISIL or ISIS).
Last month, Taliban militants killed at least 26 members of a pro-government militia in northern Afghanistan.
No group has claimed responsibility for the wedding party attack but Daesh militants have carried a string of suicide bombings and attacks on government offices, schools, and aid groups in recent years in Jalalabad, Nangarhar’s main city.