Clashes turned violent between English Defence League (EDL) protesters, counter demonstrators and police in London on Monday, when members of the far-right EDL group attempted to attack a separate left-wing demonstration.Around 1,000 EDL members took part in the demonstration which was meant to pay respects to the murdered British soldier Lee Rigby. The march went down Whitehall to Downing Street, and video footage shows some protesters doing Nazi salutes.London has seen several protests after Lee Rigby was murdered in Woolwich last week, spurring anti-Islamic rhetoric especially among right-wing groups.One police officer was treated for injuries at the scene after being hit with a bottle in Monday's clashes. The demonstrators chanted "Muslim killers off our streets!" while Metropolitan Police officers escorted them through London. EDL leader Tommy Robinson stood on a barrier attempting to calm the crowd down.Lee Rigby was run down by a vehicle before allegedly being fatally attacked by two assailants with knives and meat-cleavers in full public view. The two alleged perpetrators, Michael Adebolajo and Michael Adelowale, were filmed by eyewitnesses at the scene and video footage shows them holding their weapons with bloodied hands, waiting for police to arrive.When the police arrived the perpetrators attempted to confront them before being shot. One of them was reported to have been carrying a firearm in what the UK government labelled an act of domestic terrorism. Home Secretary Theresa May has on Monday floated plans to crack down on radical Islamic groups.