Mohammad Ismail / Reuters
The Taliban later said it had “nothing to do” with the explosion.
“We will continue our attacks even in the month of Ramadan against the US-led foreign forces and their puppet Afghan government but that doesn’t mean we will carry out attacks in places where civilians are targeted,” Taliban spokesman Zabihullah Mujahid added.
Last month, the group announced the beginning of their spring offensive, promising to build their political base in the country while focusing military assaults on the international coalition and Afghan security forces.
The explosion raises serious questions about the Afghan government’s ability to secure the war-battered nation.
U.S. and Afghan forces have been battling the Taliban insurgency for more than 15 years. The U.S. now has more than 8,000 troops in Afghanistan, training local forces and conducting counterterrorism operations.
In the past year, the Taliban have captured key districts, such as Helmand province, which U.S. and British troops had fought bitterly to return to the government.
Since most international troops withdrew at the end of 2014, the Taliban have gained ground and now control or contest about 40 percent of the country, according to U.S. estimates.
Ahmed Mengli reported from Kabul. Jason Cumming and F. Brinley Bruton reported from London. Andy Eckardt reported from Mainz, Germany. Mushtaq Yusufzai reported from Peshawar, Pakistan. Rima Abdelkader reported from New York.