However, two security guards and a policeman were hurt in the explosion and subsequent firefight with the attackers. "No UN staff members were hurt," Dan McNorton, a spokesman for UN Assistance Mission in Afghanistan in Kabul told DPA, but declined to provide further details.
The first of the bombers detonated his explosive-laden vehicle at the gate of the compound, allowing three of his comrades - equipped with machine guns and suicide vests - to enter the facility, Abdul Majeed Roozi, top commander for police forces in western Afghanistan said.
"Two guards were injured in the blast, while a policeman was injured in the firefight with the attackers," Roozi told DPA, but did not identify the guards. Both Afghan and internationals, mainly Nepalese, are employed to protect UN compounds across Afghanistan.
Noor Khan Nikzad, spokesman for provincial police chief of Herat said that three of the bombers, who were on foot, had disguised themselves in women's clothes.
He said the first blast sent the UN workers inside the compound scurrying for safety to a bunker, but a UN official, who did not want to be named, said no UN administrative personnel were inside the compound because of weekend holiday. An insurgent attack last year on a guesthouse killed five foreign UN staffers in Kabul.