Demonstrations by far right activists such as the English Defence League (EDL) fuel Islamic extremism, police have said.
Since the EDL emerged last summer, it has held demonstrations in towns and cities against Islamic extremism, with another planned for Preston city centre on Saturday November 27.
But the West Midlands counter-terrorism unit said there is evidence that violence or damage towards Muslim property associated with EDL protests encourages extremist retaliation afterwards.
Detective Superintendent John Larkin told BBC Radio 5 Live: "They look for the hook to pull people through and when the EDL have been and done what they've done, perversely they leave that behind."
Another officer said extreme sections of the EDL attacking Muslims provide "constituent parts" for those who would radicalise vulnerable people to encourage them to "go through the gateway towards being radicalised".
Also speaking to 5 Live, Policing minister Nick Herbert added: "Violence and intimidation are highly unacceptable, wherever it comes from. You can't tackle extremism by being extremist yourself. You don't prevent hatred by being hateful yourself."
Meanwhile, Lancashire Constabulary said they are working hard to ensure the Preston EDL demonstration - which is likely to attract a counter event from Unite Against Fascism - causes minimum disruption.
Police and council chiefs want people to be able to go about their daily business in the city despite the gatherings, which have caused flashpoints at similar events elsewhere in England.
Chief Superintendent Tim Jacques, divisional commander for central division, said: "We want to make sure that Preston remains open for business as usual on the day and that there is no disruption to daily life, although obviously there will be a highly visible police presence throughout the day."
Nick Lowles, chairman of the Hope Not Hate campaign, said: "This demonstrates how hate breeds hate. The EDL breeds Islamic extremism and Islamic extremism breeds the EDL. It's time to break the chain. The Government must make a stand against extremism on both sides of the divide."