A suicide bomber driving a car has targeted a Nato troop convoy in the Afghan capital, Kabul, injuring 17 civilians, reports say.
The blast took place on the main road to the airport, close to the US embassy and the diplomatic quarter.
No Nato troops had been hurt, a spokesman for the alliance told AP.
Afghan security forces have taken on much of the task of battling Taliban militants since Nato ended major combat operations last December.
A smaller contingent of foreign troops remains in the country to provide training and support to local security forces.
More than 4,000 civilians have been killed in the fighting this year, prompting fears that the toll for 2015 could exceed that recorded last year.
A massive plume of smoke was seen rising above the scene of the blast. A local health ministry official told the BBC the 17 wounded civilians included a woman and three children.
Earlier reports had indicated that several people had died in the blast, but this has not been confirmed.