London: In an attempt to enforce an ISIS-style interpretation of Islamic law, a group of extremists are allegedly cracking down on street parties in Britain by equating it to devil worship. The extremists are trying to bully and intimidate British Muslims against music and dance. According to a report in `The Sunday Times`, hardliners waved a "No music" banner and chanted "God is great" in Birmingham to disrupt festivities to mark the end of Ramadan. They boasted about "stopping da filthy dancing" and have threatened to target other events. Extremists objecting to these "Chaand Raat" festivities ? based on an Indian subcontinent tradition ? said they intervened at three separate locations across the city. In London, extremists recently confronted women travelling to a family festival to celebrate the Bangladeshi new year and warned them it was "haram", or forbidden, for them to attend. Others were told the BBC-sponsored event encouraged "sin", "fornication" and "drug-taking". The intimidatory tactics appear to be inspired by ISIS, the terrorist group that now calls itself the Islamic State and has set up a self-declared caliphate across parts of Syria and Iraq. Last week, a flag resembling that used by ISIS was flown over a housing estate in east London before being taken down by a nun. "It`s very alarming that UK-based extremists are now seeking to import an Isis-style interpretation of Islam and impose it on British citizens," said Ghaffar Hussain, the managing director of Quilliam, a counter-extremism think tank. "Banning music and dancing is completely unacceptable in a modern democracy and goes against all British values," he added.