KABUL: A bomb placed in a bag exploded on a road in downtown Kabul on Tuesday, killing a policeman and wounding two civilians, authorities said, in a relatively rare attack in the Afghan capital.

There have been few attacks in Kabul since a “ring of steel” was erected in the city before a parliamentary election last September.

The bag of explosives was planted near a bridge and detonated when the officer opened it, police said. It was unclear what the device had targeted.

Violence is at its worst across Afghanistan since a US-led invasion ousted the Taliban in 2001, with record deaths on all sides of the near-decade long conflict.

Last month, two militants wearing suicide vests attacked a bus of Afghan army officers in Kabul, killing five and wounding nine.

The Taliban claimed responsibility for that assault, the first major attack in the Afghan capital since May, when six foreign troops were killed by a large suicide car bomb blast.