CALAIS, France — Truckers, farmers, dock workers and merchants angry at the disruption caused by thousands of migrants in their midst in the northern French city of Calais blocked the main access route to Britain on Monday to press authorities to set the date to raze an overcrowded makeshift camp.

The action appeared to pay off and, despite tensions among protesters, blockades were being lifted 12 hours later after the region’s top state official reassured them that the huge, makeshift camp would be dismantled and funds made available for struggling businesses.

The action with several hundred big rigs and tractors on a main access route was the first major protest of its kind in the city, for decades a magnet for migrants trying to cross the English Channel, hopping Britain-bound trucks and trains to get across. Authorities have added police – about 2,000 – to guard roadways, and built high barbed-wire fences to protect the Eurotunnel freight trains, the port and highway, but desperate migrants are using increasingly dangerous tactics to slow trucks and hitch a ride.

The state says some 7,000 migrants are living in the camp, while aid groups have put the number at more than 9,000. All are living in a drastically downsized camp after half was razed in March.

Protesters see the migrants – from Africa, the Middle East and beyond – as an economic drain on Calais and a stain on its image.

“We are truckers, not migrant traffickers. Let’s liberate Calais together,” read a sign on the front of some big rigs.

“They damage the trucks, they break the windshield, they cut the truck sides, they climb in the truck and destroy the merchandise,” said Bertrand Wyfolscki, a trucker from St. Omer, near Calais. His list of complaints did not include the heavy fines truckers must pay if migrants are caught inside their vehicles.

Representatives of farmers, truckers and merchants came away from a meeting with the state representative of the region, Fabienne Buccio, with a new commitment – but no date – that the camp would be completely dismantled “in a single step.”

Buccio also said a special fund to help businesses in need would be activated and more than 230 extra members of security forces brought in, bringing the total to more than 2,000.

Christian Salome, head of the aid group Auberge des Migrants, which has long worked with migrants arriving in Calais, said camp dwellers were also victims.

“Refugees are the first victims of the blockading of the border,” he said, a reference to a 2003 French-British accord that effectively puts the British border in Calais, where they are stopped from entering Britain, and puts the onus of the migrant plight on France.

Hundreds of big rigs, tractors and dockers and merchants on foot blocked the main highway to the Eurotunnel and port.

“We are fed up with the migrant situation in Calais. They are increasingly aggressive,” said French trucker Blaise Paccou. “We leave in the morning. We don’t know how we’re going to return in the evening because of the rocks and metal bars being thrown at us.”

Aid groups warn that a hasty shutdown of the camp would scatter the migrants, aggravate the city’s troubles and worsen the humanitarian drama.