French police have opened an internal investigation into police actions in the northern city of Calais, after a video was released online that appears to show mistreatment of migrants.

The national police said Tuesday that its internal affairs division has opened an investigation "to quickly determine the circumstances of the (police) intervention."

A video posted online by the humanitarian group Calais Migrant Solidarity appears to show officers kicking and shoving migrants who had tried to sneak onto trucks headed to Britain.

Hundreds of migrants, from Syrians to Eritreans, make their way to Calais after their arduous journey to Europe, hoping to reach Britain, which they see as an El Dorado.

The group says the video was shot on May 5 after a visit to Calais by the French interior minister.