Three people were killed when a motorcycle bomb exploded in eastern Afghanistan on March 19 outside a rally being held by a veteran warlord who made peace with the government last year, officials said.
At least eight more people were wounded in the explosion.
The former commander, Gulbuddin Hekmatyar, was not hurt in the blast that came 10 minutes after his rally ended, in the city of Jalalabad, as people were leaving the site, Attahullah Khogyani, spokesman for the provincial governor told the media.
Hekmatyar, who served as prime minister for a period during Afghanistan's civil war in the 1990s, was in recent years allied with the Taliban.
He returned to Kabul last year under a peace deal with the government, as head of his Hizb-i-Islami party.
No group has claimed responsibility for the blast.
Nangarhar province, of which Jalalabad is capital, has in recent years become a hotbed of militants affiliated to both Islamic State and the Taliban.
The attack in Jalalabad came after at least eight people were killed in separate incidents in the capital, Kabul, and southeastern Ghazni province on March 18.