Riot police moved in Saturday to quell violent protests in Naples sparked by the first major rally in the southern city by the anti-immigrant Northern League leader.

Police fired tear gas and water cannons against the protesters, who tossed bottles, rocks and Molotov cocktails their way.

The protesters were a violent offshoot of an otherwise peaceful march through Naples by people opposed to Matteo Salvini and his anti-euro, anti-immigrant movement.

A few dozen protesters toting a banner "Naples doesn't want you" occupied the convention center on Friday where Salvini was due to speak. The Interior Ministry intervened to make sure the rally could go ahead.

The Northern League has its base in Italy's affluent north and has long criticized the tax money Rome funnels to the poorer, less-developed south. But the League in recent years has tried to make inroads in the south, capitalizing on anti-immigrant, populist sentiment and, more recently, poor showings by the Democratic Party.