Clashes have broken out in Rome on the eve of a rally by Italy's right-wing Northern League party, during a counter-protest by activists opposed to the party's anti-immigrant stand.

At least four people were injured in Friday evening's scuffles near the central Piazza del Popolo square area.

During the clashes, the demonstrators carried rubber dinghies to symbolise migrants who often use flimsy boats to cross the Mediterranean sea to Europe.

Some protesters were also seen throwing smoke bombs at police officers, who responded with batons.

Police cleared out the central square on Friday, after anti-Northern League activists occupied a nearby church ahead of Saturday's planned rally by the right-wing group.

Police appeared set to keep the square under guard until the rally by party leader Matteo Salvini begins.

"Today we came here, calling all the city of Rome, to say that we don't want Salvini in this city," Michele, an activist opposed to the Northern League party's anti-immigrant stance, said.

"That we want to take back Piazza, that it cannot remain in the hands of people like him who have for years insulted Rome, carrying out the same kind of politics that destroys our lives and is now hurling abuse at migrants in a villainous and crazy way."

Tensions over migration are particularly high as Italy copes with waves of refugees coming from Libya as well as Syria.

The Italian coastguard and navy rescue hundreds of migrants from sinking boats every week.

The Northern League is seeking to capitalise on anti-immigrant sentiments ahead of regional elections.

Source: AP