A camp of 700 to 800 migrants in the French port city of Calais was dismantled by police today in the biggest such operation since the sprawling "Jungle" shantytown was broken up four years ago. Calais continues to attract migrants from the Middle East and Africa who set up makeshift camps along the coast from where they hope to make the passage across the English Channel to Britain. Since January 1, at least 1,317 migrants have been intercepted by French authorities as they tried to reach the UK, some by swimming across the busy waterway. Tuesday's operation started before sunrise and had removed some 200 people in the first two hours, according to local authorities. Twenty-one among them were arrested. "We want to avoid a concentration and a new gathering point in Calais," Louis Le Franc, the government's top official for the northern Pas-de-Calais department, said at the scene. According to Le Franc, it was the biggest dismantling of a Calais camp since the Jungle was cleared of some 9,000 migrants between 2015 and 2016. About 150 of the evacuated migrants will be brought to reception centres in Pas-de-Calais, another 150 to other departments in northern France, and the remaining 500-odd to other regions of the country. By far the majority of the migrants are men, mainly from Somalia, Sudan, Iran, Iraq and Eritrea. "In my view, this is above all an operation to give people a safe haven. The migrants are living in this forested area in extremely difficult conditions," Le Franc said. "It was important to get the migrants out before... the winter period," he added. Northern France has long been a magnet for people seeking to smuggle themselves to Britain in small boats or in one of the tens of thousands of trucks and cars that travel daily between the countries on ferries and trains. The month of August saw this year's first drowning of a migrant trying to exit France, when the body of a Sudanese teenager trying to reach Britain with a friend in an inflatable boat was discovered on a beach. French authorities have vowed to avoid a repeat of the Jungle -- which at one point held as many as 10,000 people -- but camps have continued to spring up as migrants flee war and poverty at home to seek a better life in Europe. Rights groups have criticised police tactics, which include seizing migrants' tents and other belongings. In December 2018, France's human rights ombudsman said migrants in northern France have been subjected to "unprecedented" violations of their basic rights. As Tuesday's evacuation was under way, migrants queued for buses grouped by ethnicity or nationality, as tents, duvets, blankets, shoes and clothes were left behind in the undergrowth. "Our goal is also to fight actively against smugglers" and "the exploitation of human misery," Le Franc said. Rights associations said the operation was pointless. Maya Konforti, of the Auberge des Migrants (Migrants' Hostel) group, said the evacuated foreigners would be back "within days." "We spend a lot of money to move dozens of people in buses... but it serves absolutely no purpose. It's messaging, nothing else," she said. The migrants know that few of them qualify for asylum in France, and believing that "England is their last chance" will continue trying to get there at all costs, Konforti said. The government estimates about 1,000 migrants currently live around Calais, while support groups say the number is closer to 1,500.