A loud explosion was heard in an area close to embassies in Kabul on Friday.
Police sirens could be heard in the area but there was no immediate word of any casualties.
Bismillah Tabaan, police commander of the city's ninth district, where the explosion took place, said the cause of the blast was a suicide bombing but details, including the target, were not yet clear.
Interior Ministry spokesman Najib Danish said the cause of the explosion was a car bomb in the Qabl Bai area. At least four civilians were injured, he said.
Ghani's
peace talks offer
The attack came two days after President Ashraf Ghani offered to start peace talks with the Taliban and just over a month after an explosives-packed ambulance was blown up in the city centre, killing around 100 people.
There was no immediate claim of responsibility for the latest blast.
Much of the centre of Kabul is already a zone of concrete blast walls, razor wire and police checkpoints but security has been tightened even further in the wake of the Jan. 27 ambulance attack and another attack on the city's Intercontinental Hotel earlier in the month.