UN Secretary General Ban Ki-moon condemned the suicide attack on a UN office in Afghanistan on Saturday and praised the prompt response by Afghan and international forces.There were no casualties among UN workers in the attack, which officials said was carried out on the global body's office in the western city of Herat by four suicide bombers wearing police uniforms and burqas. A spokesman said Ban wholeheartedly commends the immediate support rendered by units of the Afghan National Security Forces and International Security Assistance Force (ISAF) whose prompt action stabilised the situation and undoubtedly saved the lives of United Nations staff members in the compound. In a statement his spokesman added that United Nations will continue to maintain its presence and programmes in Herat for the benefit of the population in need and in support of the Afghan authorities.