Police improve Premier League game between Cardiff and Chelsea at top of risk category

Police raised the risk category for Chelsea's visit to Cardiff to the highest possible level, amid fears of clashes between two groups of supporters with a history of violence.

In 2010, the Metropolitan Police had opened an investigation following a large-scale brawl involving more than 200 people outside of Stamford Bridge. He was told to be between two rival hooligan groups – the Chelsea Headhunters and Cardiff's Soul Crew.

South Wales police have informed Cardiff local institutions that the risk of disorder has increased.

They changed it from category B, or "medium risk", to category C, which indicates "high risk". There should be a strong police presence in Cardiff.

This comes at a time when the attention of football fans is focused on the grim incident involving Jack Grealish of Aston Villa. A Birmingham supporter was sentenced to 14 weeks in jail after invading the field at St Andrew's and hit the player in the head from behind.

In a letter sent to one of the owners of a Cardiff pub and seen by SportsmailThe South Wales Police writes: "Please note that the Cardiff City v Chelsea Police category has changed from CATEGORY" B "to CATEGORY" C ".

This means that the "risk" of disorder badociated with this device is now INCREASED. It is expected that about 3,000 spectators present will attend the meeting.

Chelsea have beaten Cardiff three times in a row since their infamous 2010 FA Cup clash began at 12 pm on a Saturday. The Blues triumphed 4-1 before their fans clashed.

She led the Metropolitan Police to form an investigation team under the code name "Operation Turnhill". Dozens of people were later convicted for taking part in the violence.