An anti-Islam demonstration has resulted in 10 arrests, police in the UK said.
Officers were attacked with bricks and bottles and had to act fast to prevent events from escalating, a police spokeswoman added.
Protesters from the Stop Islamisation of Europe (SIOE) group were greeted by anti-fascist groups and local people when they tried to gather outside Harrow Central Mosque in London yesterday afternoon.
Police said there were scenes of disorder and violence as different groups clashed and that the majority of those in the crowd were not members of the local community.
Supt Julia Pendry said: “What police set out to do was to police peaceful protests. Unfortunately what unfolded was a series of acts of disorder and even cases of violence. Officers came under attack from bricks and bottles and we had to deploy our staff in protective equipment a number of times.
“It is completely unacceptable for people to use the excuse of protest to break the law and behave in this way.”
Nine arrests were made for possession of offensive weapons.
The protesters gathered outside the mosque on Station Road, close to Harrow and Wealdstone Station in London, just after 5pm.
The mood soured when a gang of at least 100 pro-Islamic demonstrators broke away from the main body to chase away a small number of the anti-mosque marchers.
Police wearing riot gear responded by closing roads and kettling in the protesters outside the mosque, refusing to allow movement between their lines.
Councillor David Ashton, leader of Harrow Council, said: “We are saddened and dismayed that groups from outside the borough have come here and caused unrest.”