At least 18 people, including security personnel, were killed in a bombing in eastern Afghanistan on Thursday, hours before a three-day ceasefire was to begin for Eid Al Adha, officials said.
The ceasefire, announced by the Taliban, comes as violence has increased across the country.
US-brokered peace talks between the militant group and the Afghan government are waiting on the completion of a prisoner exchange between the two sides.
The Taliban were not responsible for the bombing, spokesman Zabihullah Mujahid said.
The explosion hit Afghan security forces in Pul-e-Alan, the capital of the eastern province of Logar, and civilian casualties are also feared, police spokesman Shahpoor Ahmadzai said.
Mr Ahmadzai said it was unclear whether it was a car or suicide bombing.
He said security troops had gathered for duty in the city to provide security during Eid Al Adha, which will be celebrated in Afghanistan on Friday.
Hasib Stanekkzai, the head of the province’s council, said it was a car-bombing and put the toll at 18 dead and 22 wounded.
Since the US and Taliban signed an agreement in February, 3,560 Afghan security personnel have been killed in attacks by militants, President Ashraf Ghani said.
The UN Assistance Mission in Afghanistan said this week that more than 1,280 civilians had been killed in the first six months of the year, mainly because of fighting between government forces and the Taliban.
The US special representative for Afghanistan, Zalmay Khalilzad, was in Kabul on Wednesday to stress the need to keep violence down after the ceasefire and to discuss progress on the prisoner exchange, the American embassy in Kabul said.