At least four Afghan civilians were killed Wednesday when a suicide bomber attacked NATO forces in eastern Afghanistan, officials said. "A bomber on a motorbike detonated his explosives next to the patrol of foreign soldiers in the Spin Jomat area of Khost city," said the Interior Ministry's spokesman Seddiq Seddiqi said. Provincial police chief Sardar Mohammad Zazai confirmed the bombing but could not give a casualty figure. "The attack occurred at 12 pm (7:30 GMT) in a crowded bazaar in the centre of the province, apparently targeting the foreign troops' convoy," Zazai was quoted as saying by DPA. A spokesman for the NATO-led military coalition also confirmed the incident. "We are aware of an explosion involving ISAF personnel in Khost city. At the moment, we are gathering information," he said, referring to the International Security Assistance Force.