Eyewitnesses said four members of Britain First, a small far-right political party, parked on a pedestrian crossing and entered the mosque a few hours ago.

They included the leader of the group Paul Golding, and a woman who was filming proceedings. The four appeared to be accompanied by a professional filmmaker who may not have been a supporter.

Some in the mosque initially thought they were members of ambulance support, since they were wearing green and had been directed to the mosque reception once they entered.

An eyewitness said: "They walked across the lobby where people pray, ignored a sign requesting people to take off their shoes, but didn't walk into the prayer room. They went to the mosque reeption and asked to speak to the Imam, who wasn't there."

The group then gave out leaflets and bibles before rushing back to their vehicle – they had left the door open.