Police said that 24 officers had been injured in the struggle to contain an outbreak of violence that has highlighted the simmering tensions on France’s council estates. As fire engines, post office vans, local council offices and a police station came under attack in Clichy-sous-Bois, northeast of Paris, one officer described the unrest as civil war.

The disturbances began when two adolescents from families of African origin died in an electricity sub-station in Clichy-sous-Bois on Thursday evening. A third youth escaped with severe burns and was taken to hospital. A rumour rapidly spread around the Chêne-Pointu estate, where the two victims had lived, that they had been chased into the sub-station by police and left there after being electrocuted.

Within four hours, hundreds of local youths were involved in widespread riots that targeted the symbols of a French state being held to blame for the deaths.

But François Mollins, the French state prosecutor, said that the two adolescents — named only as Ziad, 17, and Banou, 15 — had been caught up in a police operation that had nothing to do with them. As they had returned home with their friend, Metin, 21, after playing football, they had crossed a group of youths who were wanted for questioning after a break-in at a building site.

“They started to run because the other youths were running,” M Mollins said. “They thought they were being chased, although that was not the case.”

Metin, who was questioned in hospital, told investigators that they had climbed into the sub-station to hide. “It’s all the more dramatic for that fact that they were not delinquents and they had done nothing wrong,” M Mollins said. However, Maître Jean-Pierre Mignard, the lawyer representing the teenagers’ families, said: “Why did these youths, who were law-abiding, feel so threatened that they entered a dangerous place and not only climbed over a 2.5m (8ft) wall with barbed wire on the top, but hid inside a turbine? And why was their presence not signalled earlier?” He said that he had filed a lawsuit alleging that the authorities had committed an offence by “failing to help a person in danger”.

Last night 20 people were under arrest in connection with the rioting in Clichy-sous-Bois — a town that combines many of the factors behind France’s urban malaise: a large immigrant population, a high unemployment rate, drugs and an underground economy.

On Saturday, 500 people took part in a silent march in honour of Ziad and Banou, many wearing T-shirts that said Mort Pour Rien (Dead For Nothing). Community leaders appealed for calm, but one youth grabbed the microphone and shouted: “We want homes. We want jobs.”

Michel Thooris, spokesman for Action Police, a police union, called for the Army to help to restore order. “There’s a civil war under way in Clichy-sous-Bois,” he said. “My colleagues are not equipped or trained for street fighting.”

The violence came less than a week after Nicolas Sarkozy, the French Interior Minister, had pledged to rid council estates of their “hooligans” on a visit to Argenteuil, where he was insulted by 200 youths.

Times Recommends

• Riots as Zimbabwe turns off water supply
• Tourists told to stay away amid Venice floods
• Protest is no picnic for Carrefour customers