Hundreds of people in the northern city of Hai Phong laid siege to five policemen for two hours on Sunday after one of them reportedly caused an accident that seriously injured a motorcyclist.
Witnesses said that at around 7 p.m. they saw a police officer chasing Dang Vu Vuong, 21, who was driving a motorbike with a woman who was not wearing a helmet.
The police officer drew alongside Vuong and kicked down his motorcycle.
Vuong's suffered a broken arm and a badly bruised jaw in the incident which enraged the local population.
Hundreds of them gathered to protest the policeman's behavior. He, along with four of his fellow officers, had to take refuge in the house of a local resident for two hours before they were rescued by the Kien An District police.
Dang Vu Duc, Vuong's father, said the police have promised to review the case and assess the liabilities of all sides in the incident.
No further details about the case have been provided by the police.