Two Americans were slightly injured in an attack on a US consulate vehicle in Afghanistan's western city of Herat on Wednesday, officials said, highlighting the country's instability as NATO combat troops prepare to withdraw.
The incident came five days after insurgents attacked an Indian mission in the same city, and a day after US President Barack Obama announced the complete withdrawal of all American forces by the end of 2016.
The vehicle was on its way to the airport in Herat when an unidentified gunman on a motorbike shot at it with a rocket-propelled grenade, Basher Ahmad, chief of police for the Enjeel district, told AFP.
"The vehicle was partially damaged," said Ahmad.
A US embassy statement confirming the attack said two Americans were lightly injured and being treated at the Spanish hospital in Herat.
It added that the US was working closely with Afghan authorities to investigate the incident and bring the perpetrators to justice.
There has been no claim of responsibility so far. But most such attacks are carried out by the Taliban, who have been waging an insurgency since being ousted from power in 2001.
On Friday four insurgents launched a pre-dawn attack on India's consulate in Herat before being beaten back by security forces.
There were no casualties among Indian staff but at least two policemen were wounded when the heavily-armed attackers stormed a house close to the consulate and opened fire on the building.
Afghan President Hamid Karzai, citing a Western intelligence agency, blamed Pakistan-based militant group Lashkar-e-Taiba for that attack. It denied responsibility.
Afghanistan is in the middle of elections to choose a successor to Karzai, who has ruled since the fall of the 1996-2001 Taliban regime.
Providing security for the election is a key test for Afghan police and soldiers, with all NATO combat troops due to pull out of the country by December after more than a decade fighting the Taliban.
Some US and other foreign troops are expected to stay in a counter-terrorism role and to train Afghan forces.
On Tuesday Obama confirmed that the 32,000-strong US deployment in Afghanistan would be scaled back to around 9,800 by the start of 2015.
Those forces would be halved by the end of 2015 before eventually being scaled back to a normal embassy presence with a security assistance component by the end of 2016.