Building work began Tuesday on a wall to protect the port in the northern French city of Calais from repeated attempts by migrants to stow away on trucks heading for Britain, an AFP reporter said.

The wall, a kilometre (half a mile) long and four metres (13 feet) high, will pass within a few hundred metres of the sprawling migrant camp known as the "Jungle", which charities say now houses more than 10,000 people.