Bottles, stones and a smoke bomb have been hurled by supporters of the English Defence League (EDL) and opponents from Unite Against Fascism during protests in Bradford.
About 700 people had gathered at the Urban Gardens, in the city centre, police said.
There were also between 250-300 people at the crown court plaza for the Unite Against Fascism/We Are Bradford event. Meanwhile, 150 people were at the community event called Be Bradford – Peaceful Together, at Infirmary Fields.
Supporters of the far-right EDL threw bottles, cans and stones over a barrier towards opponents gathered opposite the Urban Gardens.
A smoke bomb launched over a temporary 8ft-high wall between the two groups landed on the ground and exploded near uniformed police officers.
A skirmish also broke out between EDL supporters and riot police.
Mounted police had pushed people away from the Urban Gardens down Market Street. Officers had also forced EDL members away from the barrier into the gardens centre.
But dozens of EDL members climbed over a police barricade and made their way into a neighbouring waste ground, where they began throwing missiles at the police. They were quickly apprehended by officers.
A West Yorkshire police spokesman said: "Missiles have been thrown in the area around the Bradford Urban Gardens; however, this has been contained and the police are utilising their resources to manage the current situation."
Buses arrived earlier today from places including Hull, Merseyside, Manchester, Stoke, Southport, Dudley, Wigan and Stockport. Many EDL protesters donned black hooded tops with the name of their home town or city emblazoned on the back.
Many supporters have rejected accusations of racism, saying they are pro-England, rather than anti-anyone. One EDL member said: "It's not about being white and proud, it's about being English and proud."
There have been fears the rallies could trigger a violent reaction to rival the 2001 riots in Bradford when 191 people were handed sentences.
