The death of a Nigerian man in police custody in China's southern city of Guangzhou sparked a violent protest by hundreds of people, state media and police said.
The man was detained after he fought with the driver of an electric bicycle over a fare on Monday, later falling unconscious in custody, and died despite efforts to revive him, Guangzhou police said in an online statement on Tuesday.
The statement said authorities were investigating the death of the unnamed man. Police could not be reached for comment on Wednesday.
The Global Times newspaper said around 500 protesters threw rocks at police vehicles and private cars, after authorities did not allow the victim's family to see the body.
The official Xinhua news agency put the number of protesters at more than 100.
Photographs posted on Chinese microblogs showed scores of people standing at an underpass and apparently blocking traffic while a line of police in blue uniforms stood guard.
A community website aimed at foreigners living in southern China, The Nanfang, claimed the African man was beaten by a group of Chinese in the argument with the driver.
Guangzhou has a relatively large African population, estimated by Chinese media reports at 200,000.
Following the protest, police in Guangzhou have urged foreigners living in the city not to disturb public order and to abide by Chinese law.