A small explosion has occurred outside the United Nations main guesthouse in the Afghan capital of Kabul, a UN spokesman said.
Mr Manoel de Almeida e Silva said the device appeared to have been placed in a garbage can outside the building in Shar-i-Naw district in central Kabul.
A police official at the scene said one Afghan was injured in the blast, which took place shortly before 8 pm local time (1530 GMT).
A UN source said the blast shattered windows of the squash court but did not cause any structural damage to the building. More than 60 people are believed to be living at the guesthouse.
Security has been stepped up outside UN buildings across Afghanistan in recent weeks after a series of incidents.
Recently a grenade was lobbed in the ground of the UN's Food and Agriculture Organisation (FAO) in the southern city of Kandahar but no one was injured.
AFP