Around 20 anti-migrant protesters were arrested in the French port of Calais Saturday after scuffles with police at a banned rally in support of a Europe-wide initiative by the Islamophobic Pegida movement.

A crowd of around 150 protesters had gathered in central Calais carrying signs such as "This is our home," waving the French flag and singing the national anthem, despite the government issuing a ban on demonstrations earlier this week.

"Some groups began to circulate in the city centre, mainly far-right, neo-Nazi types," regional official Etienne Desplanques told AFP.

Police issued warnings for the demonstrators to disperse and then fired tear gas to break up the rally. There were several skirmishes with police, an AFP correspondent at the scene reported.

"We have had a series of arrests, in all about 20," said Desplanques, adding that the figure could go higher.

One of those arrested was Christian Piquemal,  a former general with the prestigious French foreign legion from 1994 to 1999, an AFP photographer reported.

Calais has become a hotspot of Europe's refugee crisis. Around 3,700 migrants are living in a camp on the outskirts of the city, nicknamed the "Jungle", hoping to smuggle themselves across the Channel to Britain on lorries or trains. 

Anti-Islamic group Pegida, which began as a movement in Germany in mid-2014 and has since spread to France and other European countries, has called on members and sympathisers across Europe to join marches on Saturday.

Ahead of the protest, Interior Minister Bernard Cazeneuve on Wednesday called on authorities in Calais to prevent all demonstrations "regardless of the organisers".

He said the ban particularly covered "all these groups that create tensions, division and violence" and would last as long as necessary. 

Pegida, an acronym for "Patriotic Europeans Against the Islamisation of the Occident," has said it expects demonstrations to take place in 14 European countries.

In France, another anti-migrant rally took place in the southern city of Montepellier. Around 200 people joined the demonstration which organiser Richard Roudier said was aimed at "saving our country... we are against migrants, the islamisation of our country."

Also on Saturday, in a relatively rare attempt to reach England by sea, four migrants were rescued from their sinking boat in the Channel thanks to a fifth migrant who made it to shore and alerted rescuers.