The latest in a string of incidents of foreigners being attacked in Vietnam.
Police in Vietnam's northern tourist town of Sa Pa are investigating an alleged attack on a foreign man following a minor road accident.
A video of the incident was shared on social media, and police are trying to verify the license plate and identity of the attackers, who were filmed hitting a foreign man of around 50 years old.
Eyewitnesses said the man was from the Netherlands and had been driving a motorbike when a minor collision occurred with a car from Hanoi. All five men traveling in the car, including the driver, jumped out and assaulted the man.
A woman traveling with the foreigner tried to prevent the attack, but was unable to, so she used a helmet to fight back, a local said.
Bystanders eventually stepped in to break up the fight as traffic came to a standstill. The tourist suffered severe bruising to his face.
A World Economic Forum report on travel and tourism competitiveness earlier this year ranked Vietnam the third safest country in Southeast Asia, but recent attacks on foreigners might sabotage that charm.
Last month, a 27-year-old American man was beaten in Hanoi after he banged on the door of a car to notify the driver that his foot had been run over. The driver and a friend used a crash helmet to beat him and anyone who tried to intervene. Both have been arrested on criminal charges.
Police in Ho Chi Minh City also detained a man last week for fatally stabbing an American tourist, allegedly over an argument about the poor quality of drugs the foreigner had bought from him.