Liverpool fans threw flare into Manchester United section during Capital One Cup clash- VIDEO By Laurie Whitwell The Football Association has contacted Liverpool and Manchester United after footage emerged of a lit flare being thrown from the travelling section at Old Trafford onto home fans below. Stark warnings have been issued about the dangers of using the "2,000-degree" flames as missiles after the shocking incident during the Capital One Cup tie on Wednesday. Video captured from the North Stand clearly shows a red flare being lit high up in the East Stand of the ground, housing 7,200 Liverpool supporters, and launched beyond a cordon of stewards into the United section, provoking jeers and boos in response. Scroll down to watch the video Danger: In this video grab a flare can clearly be seen being thrown from one section of Old Trafford into another Seeing Red: Smoke can be seen in the Liverpool end at Old Trafford during Wednesday's Capital One Cup game - IT IS NOT SUGGESTED ANYONE PICTURED HERE SET OFF THE FLARE Smoking: Gas can be seen billowing around the upper tier of Manchester United's stadium In total four flares were sparked during the third round tie, won 1-0 by David Moyes's side, and Greater Manchester Police have confirmed there were issues with smoke bombs, particularly in the Liverpool end, despite the presence of police dogs and searches. Ten arrests were made but suggested this was on the low side for a match of such magnitude with a crowd in excess of 70,000. None of the arrests were in connection with the flare-throwing incident. Matchwinner: Javier Hernandez settled matters on the pitch with the only goal of the game Comeback: Controversial Liverpool striker Luis Suarez made a return to action on Wednesday night "The Football Association has contacted Manchester United and Liverpool to seek their observations into the incidents with flares during the Capital One Cup tie," an FA spokesman said. The FA, Premier League and Football League are currently working together on the issue of flares, in conjunction with the Fire Service and St John Ambulance, in an effort to alert supporters to the potential dangers. The Premier League issued a statement stressing the "extremely dangerous" nature of flares and said work would be increased on persuading fans to stop using them. It read: "They burn at close to 2,000 degrees and we have been made aware of several incidents where fans have sustained injuries by igniting them. They also generate such large quantities of smoke that they negatively impact on people's enjoyment of the game and can cause panic and breathing difficulties for fans sat close to them.' Manchester United have yet to receive any complaints from fans about the incident captured in the footage. Both clubs have a week to respond to the FA but it is simply a fact-gathering exercise and there is no chance of sanctions against Liverpool or United. Instead, any information gathered will be used to address supporter groups and encourage them to stop bringing in flares. Growing problem: United defender Rio Ferdinand was struck by a coin and flares were thrown onto the pitch by Manchester City fans in the derby at the Etihad Stadium last season Flare-ing up: Arsenal fans let off a flare at Stamford Bridge as their side take on Chelsea Setting off: Bayern Munich's hardcore following show support for their side with smoke bombs and flares Shining light: Rio Ferdinand surrounded by flares in England's World Cup qualifier in Ukraine in 2009 Green with envy: A smoke flare is thrown onto the pitch in England's friendly against Ireland this year