A car bomb exploded outside a United Nations office in the southern Afghan city of Kandahar on Tuesday, wounding at least one person, a U.N. official said.

The explosion, in Kandahar's upscale residential area of Shehr-e-Nau, occurred in a parked in front of a home being used as a workplace by the U.N. Office Project Support (search), said Siddiqullah, an Afghan who is in charge of humanitarian operations for the United Nations in southern Afghanistan.

The blast, which occurred minutes after U.N. workers had left the building at the end of their work day, smashed a front gate, cracked walls in the building and broke its windows, said Siddiqullah.

No one was hurt there, but a man driving by on a motorcycle at the time was wounded by the blast, said Siddiquallah, who like many Afghans only uses one name.

It was unclear who had parked the car there, and there was no immediate claim of responsibility.

Kandahar is a former stronghold of the Taliban (search) militia which ruled most of Afghanistan before it was driven out of power by a U.S.-led invasion and replaced by an Afghan government supported by the coalition.

Taliban has been blamed for other attacks in Kandahar (search) since losing power, and its supporters often fight there with Afghan security forces and coalition troops.

However, the U.N. Office Project Support has continued to work in the area, building roads and drains.