French police arrested 70 people at a banned pro-Palestinian Arab protest in central Paris on Saturday that degenerated into clashes between demonstrators and armor-clad riot squads, AFP reports.

The rally had drawn 4,000 people to the capital's Place de la Republique, the interior ministry said, while organizers put the turnout at 10,000.

Police who stepped in to disperse the rally responded with tear gas when they were targeted with rocks and other projectiles. About 12 police were slightly injured.

Interior Minister Bernard Cazeneuve said while the young people protesting had been mostly peaceful, "there were troublemakers at this demonstration", some of whom had come armed with the intention to cause violence.

"There were 70 arrests and 30 (of them) have been detained, some of whom had significant weapons, including clubs... and knuckle-dusters," AFP quoted him as having said.

The demonstration against Israel's operation in Gaza came after other protests last weekend in Paris and a suburb that had also initially been banned descended into chaos.

French police announced on Friday that the protest was banned. The organizers had tried going to court to get the ban overturned, but they were unsuccessful and Cazeneuve had warned that they would be held "responsible for any unrest... and liable to penal sanctions".

A police source said officers had been under strict orders to take in people who made anti-Jewish statements or gestures.

Similar earlier demonstrations saw hundreds of Muslim extremists attacked a major synagogue in Paris, provoking clashes with Jewish youths who rushed to defend the site and worshippers trapped inside.

Elsewhere in the country, nearly 10,000 people turned out in the eastern city of Lyon for a similar protest, though it was not banned and went off peacefully, according to AFP.

In the southern cities of Marseille and Nice, hundreds also turned out in support for Palestinian Arabs.