Calais people-smugglers block route with tree
Footage of armed people-smugglers going to extreme lengths to get migrants in Calais across the Channel to Kent has been recorded by the BBC.
Masked men wielding large sticks are shown blocking the main route to the French port with a felled tree and threatening motorists with violence.
BBC South East witnessed migrants being directed to break into lorries brought to a sudden halt by the men.
Calais authorities said the road was a "no-go zone" between midnight and 6am.
An additional 140 French police officers are due to be drafted into Calais from this weekend.
BBC South East special correspondent Colin Campbell and his producer were driving along the main motorway into Calais on Wednesday when they were brought to a halt by a tree that had been dragged on to the dual carriageway at about 04:00 local time by the people-traffickers.
The BBC team witnessed the smugglers, who they described as "ruthless and territorial", controlling the situation armed with large sticks.
The smugglers directed about 20 migrants to lorries queuing behind their car at which point another lorry overtakes them, coming to a screeching halt at the makeshift roadblock.
They were seen to hit the lorry before one turned his attention to a migrant waiting in the bushes, and attacked him.
It is not known whether any of the migrants were successful in getting on to the trucks.
A short time later French police were seen searching the side of the road with spotlights as the debris was cleared away.
There were other attacks that night, which were spread out over a wide area of the motorway.
Analysis from the scene
BBC South East special correspondent Colin Campbell
With increased security and razor wire fencing surrounding Calais' migrant camp and the seaport, those seeking to get to Britain illegally are travelling further out of the French port to stow away inside UK-bound trucks.
This latest tactic is straightforward.
Debris is placed on main motorways and vehicles are forced to stop.
The consequence of this is the Calais migrant crisis is now enveloping all motorists causing significant road chaos and fear.
There are an estimated 9,000 migrants living in the camps around Calais, with many paying smugglers to get them into the UK.
Calais Police union representative Gilles Debove said there needed to be measures to prevent people from getting on to the road.
"Effectively the violence is getting worse: migrants are trying to get out any way they can because you don't want to spend the winter here in Calais."
Vincent Berton, the deputy prefect of Pas de Calais, said: "We're trying to deal as effectively as we can with the situation in Calais.
"Our resources are stretched but we're going to have reinforcements to improve this situation."