As rioters hurled bricks, bottles and fireworks in a frenzy of violence in Plymouth, members of the local mosque were taking no chances. The riots, which mirrored those that have scarred so many communities in the past week, broke out on the high street on Monday as 150 officers in riot gear and with dogs sought to keep apart far-right rioters and Stand Up to Racism demonstrators in the city centre. Battles were fought near shops in Royal Parade opposite the Guildhall and the surrounding area in what one senior officer described as “sustained violence”. Just 15 minutes walk away, members of the local mosque were braced. About 50 to 60 people had turned up to protect the Plymouth Islamic Education Trust (Piety) building that houses the mosque where 1,000 regularly attend Friday prayers, said the centre’s director, Mohamed Muganzi. “They came of their own volition because they were worried enough about what might happen. They had seen what had happened elsewhere.” Last week, someone smashed the door to the centre, an act captured on CCTV and which Muganzi believes was motivated by what was happening in other towns. On Monday, Piety hired private security. Those community members who turned up to protect the building were “the second line of defence, after the police”, said Muganzi. Thankfully, he said, they were not needed as the building was not targeted. “But it really breaks my heart that there are some community members who feel this afraid.” Police and council leaders met Muslim community representatives on Tuesday to offer support and reassurances. The police, said Muganzi, had done a “tremendous job”. Three police officers sustained minor injuries, a police van was damaged and two members of the public were taken to hospital after the clashes on Monday. Six people have so far been arrested in connection with the violence, during which bricks were torn up from pavements and fireworks set off. More arrests are likely to follow as Devon and Cornwall police have appealed for phone footage to help identify those involved. The assistant chief constable Nikki Leaper said she was “absolutely” expecting more arrests. Among those who featured in social media posts from the anti-migrant protest earlier was Nick Tenconi, the interim leader of Ukip, who was filmed in Plymouth shouting slogans with a loudspeaker. By Tuesday the only visible evidence of what had occurred was a smashed window at TK Maxx in Royal Parade. City council staff reported at 4am for clean-up duty in the city centre and the areas around the Hoe, with mechanical sweepers cleaning up debris from rocks and glass bottles along with small paving stones that had been ripped from the ground. A number of bins had also been damaged. By the time people began arriving for work at 8am, the team of nine had cleaned up a huge area. “It is thanks to their magnificent efforts Plymouth is once again looking spick and span in the summer sunshine,” said Sally Haydon, the council’s cabinet member for community safety. Jemima Laing, the deputy leader of Plymouth city council, called the violence “thuggery on tour”, with many coming from outside the city to cause trouble. She blamed the riots on a “small minority of thugs” who she said would be brought to justice. “While most protesters were peaceful, we are appalled by a small number of individuals who engaged in aggressive, violent and abusive behaviour. I remain incredibly angry on behalf of Plymouth that so many people from outside our city felt emboldened to come here and cause disruption and unrest. Thuggery on tour is not acceptable,” she said. Devon and Cornwall police said: “Our approach to this operation was to enable peaceful protests, but people who were intent on committing public order or criminal offences have and will be dealt with robustly. This is the style of policing that we have delivered and what our communities expect. “Violence will not be tolerated, hate will not be tolerated, and we will continue to work with our partners to keep the people of Devon, Cornwall and the Isles of Scilly safe and reduce antisocial behaviour. “We will continue to take positive action against individuals in breach of the law and have carried out arrests for a range of public order offences and assaults following today’s events. We will also be following up on post-investigative inquiries throughout the coming days.”