Hundreds of high-school pupils have protested against police brutality in France, blocking the entrances to a dozen schools in the capital, Paris, in the latest in a series of rallies triggered by the suspected rape of a young black man with a police baton.

Police reported eight arrests on Thursday, according to the Reuters news agency, after isolated skirmishes with youths who hurled objects and damaged property on the fringes of what otherwise appeared to have been a relatively peaceful demonstration.

The protesters are angry over the alleged rape of a 22-year-old man during a February 2 arrest in an area north of Paris where large numbers of immigrants live. The man, identified only as Theo, remains in hospital with injuries to his anus and head.

Four police officers have been suspended pending an inquiry into the incident. One has been placed under formal investigation for suspected rape and three others for unnecessary use of force.

The Paris school authority on Thursday said more than 10 schools had been targeted by youths who piled up rubbish bins and other objects at the entrance gates. In one case, a deputy school director was injured when protesters hurled a fire extinguisher.

The protest, which went on without authorisation by the police, comes two months before a presidential election where far-right leader Marine Le Pen, leader of the anti-immigrant National Front party, is tipped to win the first round but lose the run-off vote that takes place on May 7.

'Revenge for Theo!'

Theo has called for public calm and his family has said they have faith in the French justice system.

One of the banners carried at Thursday's rally read: "Revenge for Theo!"

READ MORE: Paris police say rape of black man an 'accident'

Social media networks showed signs of skirmishes on the fringes of the rally in the Place de la Nation square in the east of Paris, where riot police in protective gear advanced on groups of mostly hooded youths in sidestreet confrontations.

A helicopter flew overhead and tear gas clouds rose into the air above that square towards the end of the rally.

So far the protests have not snowballed to the extent of the unrest that 12 years ago drew global attention to the stark contrast between wealthy Paris and the suburbs that surround it.