French youths clash with officers and blockade schools in protest over alleged police rape of black youth

Paris teenagers blockaded 16 secondary schools and clashed with riot officers in protests against police violence prompted by the alleged rape of a young black man with a truncheon.

Police fired tear gas on small groups of protesters and detained 21 people after a crowd of about 1,000 youths marched on the Place de la Nation, a square in eastern Paris linked to the French Revolution.

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

Flares were lit by protesters, some masked to hide their identity and protect themselves from the tear gas.

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

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

One group carried a banner reading "Vengeance for Theo."

Another five arrests were carried out in the Paris area.

Youths piled up rubbish bins and other objects at the entrance gates to 16 schools. In one case, a deputy school director was injured when protesters hurled a fire extinguisher. Thousands of pupils were told to stay at home following a call on social media to stage protests, despite lack of police authorisation.

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. All deny wrongdoing.

There were fears the protests could snowball into the type of unrest that saw three weeks of nightly riots in high-immigrant suburbs ringing major cities around France 12 years ago, which drew global attention.

Theo, who was hospitalised for two weeks, has become a symbol for minorities standing up to police violence. His last name has not been publicly released.

Najat Vallaud-Belkacem, the French education minister, called for calm, saying: "There is a very understandable emotion among young people regarding the Theo affair, but justice must be left to do its work." She promised to mete out tough punishment to any youths who cause vandalism or violence.