Several thousand people have marched through the northern Italian city of Milan in a protest against rising numbers of immigrants -- blaming them for a crime wave in the city.

The protest was organised by the separatist Northern League and followed a similar one on Saturday by the main centre-right opposition group, the Freedom Alliance.

Last Tuesday the prime minister, Massimo D'Alema, announced the deployment of eight-hundred extra police in Milan, but warned against what he called racist hysteria.

Meanwhile coastguards said that about four hundred illegal immigrants were picked up in southern Italy over the weekend.