German Chancellor Angela Merkel backed stricter laws to expel convicted refugees, as clashes erupted at far-right protests in Cologne over a rash of sexual assaults blamed on asylum seekers, AFP reports.

Cologne police said they have now recorded 379 cases of New Year's Eve violence - ranging from groping to theft to two reported rapes - with asylum seekers and illegal migrants making up the majority of suspects.

Vowing tough action, Merkel declared that any refugee handed a jail term - even if it was a suspended sentence - should be kicked out of the country.