KABUL, Afghanistan — A suicide bomber struck the home of a tribal elder in the eastern Afghan city of Jalalabad Sunday morning, killing at least 13 people, an official said. It was the latest attack in the increasingly volatile Nangarhar Province.

The attacker, who at midafternoon had not been identified, targeted the home of Malik Usman Shinwari, the father of two prominent government officials, said Attaullah Khogeyanai, a spokesman for the provincial governor. Mr. Shinwari was injured in the attack, but his wounds did not appear to be life-threatening, people who were present said. He was taken by helicopter to Kabul, the Afghan capital, for treatment.

Najeebullah Kamawal, head of the Nangarhar public health directorate, said at least 14 civilians had been wounded and three were in critical condition.

The attack took place as Mr. Shinwari and visitors celebrated the return of another of his sons, who had been released from Taliban captivity. The bomber infiltrated the gathering and detonated his explosives but fell short of his apparent intended victims, the people who were at the scene said. Mr. Shinwari’s sons Obaidullah, a provincial council member, and Hameedullah, a district mayor, were unharmed, the provincial governor’s office said.