Afghan officials say the toll from a suicide bombing in Kabul has climbed to 31 killed and 54 wounded.
Afghan health officials had originally placed the death toll from the April 22 attack at four dead and 15 wounded.
The suicide bomber targeted a crowd that had gathered to pick up national identification cards at a voter-registration center in the capital.
The extremist group Islamic State claimed responsibility for the attack through its mouthpiece, the Amaq news agency. Amaq did not provide evidence to back up its claim.
The attack took place in in a heavily Shi'ite-populated neighborhood in the west of the city, which has been previously hit by attacks claimed by the extremist group Islamic State.
Afghan President Ashraf Ghani and Chief Executive Abdullah Abdullah were among those to condemn the attack.
Afghanistan on April 14 began registering voters for long-delayed legislative elections scheduled for October.
Election officials have acknowledged that security is a major concern as the Taliban and other militant groups control large swathes of the country.