Police officers stopped a car whose driver was highly intoxicated in the French town of Joué-les-Tours. The allegedly uncooperative driver was being subdued by an officer, when a female passenger reportedly bit one of the officers.
The officer started hitting the woman with his baton.
He then took a can of tear gas from his vehicle and sprayed it on the woman's face.
He also sprayed another female passenger's face with tear gas.
French prosecutors have launched an investigation into the case after the video posted by a user, Nasser tkt, caused many French observers to condemn the officer's actions.
However, a police union told AFP that the officer had responded after being pinned down by the woman and bitten three times.
The Local reported:
"The video may seem shocking but we don't know the context," Gaelle James of France's second-largest police union, Synergie Officiers, told AFP.
"He clubbed her to get away," James said. "He had to intervene under very difficult conditions. We cannot forget that violence against the police is increasing. This doesn't shock me."