The United Nations has issued a new warning of a "dramatic increase" in the numbers of migrants arriving in southern Europe placing a "huge strain" on communities there.

The UN's latest estimate is that more than 100,000 people have crossed the Mediterranean from north Africa this year.

Many migrants have been heading north from camps in Italy and Greece. Those searching for work in the UK have been reaching the French port of Calais where the pressure is growing by the day.

Fergal Keane reports from Calais.