Four people died in a rear-end collision between a police car and a truck Thursday in south China's Guangxi Zhuang Autonomous Region, local authorities said. The four dead were two police officers and two parapolice. Another one in the police car was injured. The accident occurred at around 6 p.m. Thursday on the Lanzhou- Haikou Highway, 20 km from Mashan County in Nanning, capital of Guangxi. The police car was on fire. Local authorities did not reveal how many people were on the truck or whether they were injured. They said the police car belonged to the public security department in Zhuhai City, neighboring Guangdong Province. Police are investigating the accident. 