Hooded youths armed with iron bars have gone on the rampage in secondary schools in the tinderbox suburbs north of Paris, sparking more than 50 arrests.

The violence prompted the far-Right Front National to claim that the government had lost control in suburbs around France, prey to lawlessness, drug dealing and ethnic and religious tensions.

The teenagers threw stones at police cars, started fires and lobbed smoke bombs in three sixth form colleges in the Paris suburb of Saint-Denis.

Some 54 were under arrest on Wednesday, but by evening 48 were released and eight were facing charges.

The riots the previous day marked an unprecedented escalation in tensions following a string of protests against alleged police violence. The Paris regional council put the cost of the damage at at €70,000.