A group of 300 Russian hooligans arrived armed to attack football fans in an organised assault which left 19 British people in hospital, four in a critical condition, The Independent can reveal.

Thugs wearing black T-shirts carried bum bags containing equipment for assaults, including gum shields, fighting equipment and mixed martial arts gloves when they arrived in Marseille on Saturday afternooon. They seized upon the chaos caused by gang violence which had already started in the centre of Marseille – between rival fans of Olympique Marseille and Paris Saint Germain – to launch indiscriminate attacks on English fans.

English supporters ran for their lives but the Russians outnumbered them and were quicker and stronger, unleashing extraordinary violence on them using any available weapon, sources told The Independent.

British police, who have no jurisdiction on French soil and can only attempt to moderate the way fans behave to assist the French, were caught up in the violence. The first Briton to be felled by the Russian gang was given first aid by a British officer. British police also provided bandages and medical equipment to fans.

Russia and England fans clash at Euro 2016 – in pictures Show all 15 1 /15 Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 : An England fan kicks a tear gas canister as fans clash with police ahead of the game against Russia GETTY Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 : England fans throw bottles and clash with police ahead of the game against Russia GETTY Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 Flares are lit on the stands after Russia scored a goal during the Euro 2016 Group B soccer match between England and Russia, AP Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 Supporters clash at the end of the Euro 2016 Group B soccer match between England and Russia, AP Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 An England fan is arrested after clashing with police ahead of the game against Russia GETTY Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 Russian supporters charges at England fans in the stands at the end of the Euro 2016 Group B soccer match between England and Russia AP Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 Russian fan smashes a chair over an England supporter as another attacks him on the ground as they clash ahead of the game against Russia GETTY Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 Supporters clash at the end of the Euro 2016 Group B soccer match between England and Russia, AP Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 Fans try and escape at the end of the Euro 2016 Group B soccer match between England and Russia, AP Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 Supporters clash at the end of the Euro 2016 Group B soccer match between England and Russia, AP Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 Flares are lit at the end of the Euro 2016 Group B soccer match between England and Russia, GETTY Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 Supporters clash at the end of the Euro 2016 Group B soccer match between England and Russia, GETTY Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 Supporters clash at the end of the Euro 2016 Group B soccer match between England and Russia, GETTY Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 Fans try and escape at the end of the Euro 2016 Group B soccer match between England and Russia, GETTY Russia and England fans clash at Euro 2016 – in pictures Russia and England fans clash at Euro 2016 england fans clash with police ahead of the game against Russia GETTY

The Russians seemed to be organised around individual clubs. Their black T-shirts carried the names of the Lokomotiv Moscow and CSKA Moscow sides.

Uefa today made it clear that it suspects Russian fans were the architects of the scenes of extraordinary violence which marred England’s opening European Championship fixture against Russia on Saturday night, and said it viewed the clashes before the game with “utter disgust”.

The governing body has major questions to answer itself – including why it had allowed a match which carried serious risk of violence to be staged on the Mediterranean coast at 9pm on a Saturday evening and why there was so little segregation to prevent Russian fans effectively chasing the English out of the stadium after the game.

Neither British nor French police had any way of influencing the timing of the fixture. It had been made clear as soon as the Euro 2016 draw was made that times and locations would be designated for the matches according to the order teams’ names came out of the hat.

British police have liaised strongly with their French counterparts and will continue to provide as much help as they can in the coming days, as the investigation into Saturday’s events gets under way. The London-based intelligence gathering centre set up by the UK Football Policing Unit will use images from media and social media to attempt to help identify any perpetrators of the violence carried out on English fans. The same material will be used to apply for banning orders for England fans, where appropriate.

There is no sense that this problem will be isolated to Marseille. The authorities have suggested England fans travel to Lille to drink before Thursday’s game against Wales, because of an alcohol ban in nearby Lens, where the game takes place. Russia play Slovakia on Wednesday - in Lille.

Uefa said in a statement that it had “serious concerns” about incidents at the end of the match inside Stade Velodrome, including the throwing of flares onto the pitch from the Russian contingent and subsequent flight of English fans – seemingly with Russians chasing.

“This kind of behaviour is totally unacceptable and has no place in football," Uefa said. "Disciplinary proceedings have been opened against the Russian Football Union (RFU) for the following events occurring inside the stadium: crowd disturbances, setting off of fireworks and throwing of missiles. A decision on the sanctions to be imposed will be made within the next few days, once the RFU has been able to submit written statements and evidence.