Violent clashes broke out in the refugee camp outside Calais today, as French authorities began to demolish the southern part of the so-called 'Jungle'.

Charities working in the camp have reported a heavy police presence armed with rubber bullets. Help Refugees UK said teams were dismantling shelters using crowbars, mallets and Stanley knives, and shared a video showing tear gas being used against people trying to stop the demolition.

"This is shocking and a long way away from the humanitarian dismantling of the camp promised by the Minister of the Interior last week," the charity said.

Another video posted to Facebook showed a water cannon being used by French police.

Reuters reports that tear gas was fired by police around midday and between 150-200 activists and migrants threw stones. Three shelters were reportedly set on fire, while one person has been arrested for trying to stop workers from clearing the site.

A court in Lille ruled last Thursday that the Calais prefecture could legally demolish a large part of the Jungle, and evict its inhabitants, believed to include more than 3,400 refugees and migrants. It did, however, stipulate that "common social areas" – understood to include a church, several mosques and schools, a women and children's centre and a library – would not be destroyed.

Interior Minister Bernard Cazeneuve said displaced persons would be relocated to converted shipping containers in the northern part of the Jungle, or to a number of other refugee centres around France.

Campaigners, however, say this is a poor alternative to the Jungle, where inhabitants have set up shops, restaurants and cafés. There are particular concerns for unaccompanied minors, more than 300 of whom live in the southern part of the camp.

Charity CalAid said it was "appalled and saddened" by the demolitions carried out today.

"French demolition teams are in the Southern section of the camp ripping apart shelters and moving residents out of the camp," it said in a post to its Facebook page.

"Rubber bullets and tear gas for the people, mallets and Stanley knives for their homes. Volunteers being prevented from entering the camp. Refugees hitting the road with nothing but a sleeping bag.

"French Minister of the Interior, Bernard Cazenove [sic], promised 'humanitarian' methods of relocating the residents of the camp – there is nothing humanitarian in the actions of the authorities today."