At least 12 people died in a car bombing in the eastern Afghan city of Khost on May 27, the first day of the Muslim holy month of Ramadan.
Provincial police chief Faizullah Ghairat said 12 people were killed and eight others injured, adding that the injured are in critical condition.
According to Afghan Interior Ministry spokesman Najib Danish, 13 people were killed.
Earlier, Danish said 18 people were killed, but he revised the death toll in a phone call to news agency dpa.
Khost police chief Faizullah Ghairat said the attack targeted a convoy of local militia forces trained by U.S. forces.
Ghairat told RFE/RL’s Radio Free Afghanistan that there were two children among the injured.
Afghan President Ashraf Ghani condemned the attack.
Taliban militants have claimed responsibility for the bombing. Taliban spokesman Zabihullah Mujahid said the bombing was carried out by Hafiz Edris Khosti and killed 22 soldiers.
The attack comes a day after at least 15 Afghan soldiers were killed when Taliban fighters attacked their base in Kandahar.