NANNING - Two police officers are being interrogated for driving a police car into seven pedestrians and bike riders on Tuesday in Nanning, capital of Southwest China's Guangxi Zhuang autonomous region.

According to investigators with the Nanning Municipal Public Security Bureau, blood tests have proven the driver of the car did not have alcohol in his system at the time of the incident.

Hospital sources said two of the victims were severely injured, but the injuries were not life threatening.

Investigators said the two policemen were on their way back to the Jiangnan branch of the Nanjing bureau at 5 p.m. on Tuesday, when their vehicle hit the civilians at a road section near Tingzi Vegetable Market.

A spokesman said the bureau will run a fair investigation of the incident, and make timely reports of the results to the public.