A powerful blast hit downtown Kabul as a suicide car bomber targeted foreign military vehicles, officials said, with casualties feared.
The blast came on the main road to the airport, around 500 metres (550 yards) from the US embassy and near a base for foreign troops.
“It was a suicide car bomber targeting a convoy of foreign forces in Kabul,” interior ministry spokesman Sediq Sediqqi said.
Kabul deputy police chief Sayed Gul Aga Rohani confirmed the attack and said there were casualties, but no details were immediately available.
The blast comes hours after a suicide truck bomb targeted a police headquarters in the restive southern province of Helmand, killing at least two people.
Afghan troops and police are battling the Taliban in the first “fighting season” since NATO ended its combat mission and left local forces to take charge of security.
NATO’s combat mission formally ended in December after 13 years, but a small follow-up foreign force named Resolute Support has stayed on to train and support local security forces.