Police sealed off the area after the attack
Afghan security forces have shot dead two militants who attacked a charity office in the southern city of Lashkar Gah, officials say.
They say the two men, wearing burkas, were killed before they could detonate their explosives-laden vests.
A woman working for the International Relief and Development charity and a guard were injured in the attack.
Lashkar Gah is near Marjah in Helmand province, the focus of a major Nato-led offensive against the Taliban.
Last Saturday, suicide bombers launched an assault on the city of Kandahar, in the neighbouring province, which left at least 35 people dead.
A Taliban spokesman said the attacks were in response to a planned major offensive by US and Nato forces against militants in the Kandahar province.