Calais has long been a jumping off point for migrants seeking to reach Britain, and has been a flashpoint for police operations.

Around 300 police were mobilised for operations carried out early Tuesday at the Turquerie camp, said prefect Jacques Billant, the Pas-de-Calais region’s top official.

The expulsion, which occurred following a court order, was “considered necessary due to the large number of migrants” involved in “significant disturbances… including knife crime,” Billant said.

He added that the operation was carried out without major clashes.

The operation ended with over 500 people agreeing to be placed in temporary housing, the Calais prefect said in a statement, adding that about 20 others were arrested.

The same camp was also cleared in May and June, when about 350 people were staying there.

Madeleine Debressy, from the group Human Rights Observers (HRO), said the intent was to wear people out by repeatedly displacing them.

The people who have been relocated to temporary housing will return to Calais, because they want to go to England, Debressy added.

While the expulsion took place, migrant crossings towards England continued, taking advantage of calm weather.

Some 24,000 migrants have made the crossing to southern England from northern France in flimsy and unsuitable craft so far this year.

The governments in both London and Paris have promised to crack down on people-smuggling gangs behind the crossings.

Four migrant boats set sail towards England on Tuesday, according to local authorities in France.

Gendarmerie police boats assisted with one vessel that was sinking and took its stranded passengers back to French soil.