A suicide bomber has killed at least 13 people at the Jalalabad home of a prominent local politician who backs President Ashraf Ghani's peace talks.
Tribal elders had gathered at the home of Obaiduallah Shinwari to celebrate his brother's release from months of captivity by the Taliban.
The released brother and his father are among 14 people injured in the attack.
It comes ahead of a second round of efforts to restart peace talks with the Taliban. They have denied the attack.
Jalalabad is the capital of Nangarhar province, where two districts are controlled, or at least influenced, by the Islamic State group - a rival of Taliban.
The Afghan government has been locked in a bloody conflict with Taliban militants for more than a decade.
Key Afghan, Pakistani, Chinese and US officials met last week for talks aimed at establishing a roadmap for peace between the Afghanistan government and the Taliban.
However, the Taliban, who are divided by factional infighting, did not attend that session.
Peace talks between the Afghan government and the Taliban collapsed last year, after news emerged that Taliban leader Mullah Omar had in fact died in 2013.
His deputy Mullah Mansour was declared leader in July - but a number of senior Taliban commanders refused to pledge allegiance to him and a faction opposed to him was set up under Mullah Mohammad Rasool.
The Taliban has launched several high-profile attacks in recent months.
In December, the militant group launched an attack on the strategic district of Sangin. It later seized and blew up the police headquarters and governor's compound.
And in September, the Taliban briefly overran the northern Afghan city of Kunduz, in one of their biggest victories since 2001.