Bottles and smoke flares have been thrown towards police vehicles as a third protest got underway outside a hotel in Essex believed to be housing asylum seekers.
More than 100 demonstrators gathered outside the Bell Hotel in Epping on Sunday following two previous demonstrations earlier in the week.
One person has been arrested, police said, and has been taken into custody.
Some protesters set off flares in blue and red, while others held signs which read "deport foreign criminals", "we go home when they go back" and "defend our girls".
Essex Police announced, before the protest, that it would order demonstrators to remove face coverings when requested under section 60AA of the Criminal Justice and Public Order Act 1994. Anyone who refuses to remove a face mask when asked to do so is likely to be arrested and could be imprisoned if convicted, the force said.
The force said earlier this evening that it had a “full policing plan in place to ensure the safety of everyone who is attending”.
A spokesperson for Essex Police said: “To protect the public this evening we have put a power in place to require the removal of face coverings.
“If you are planning to protest peacefully about issues which are important to you and your community then this is entirely lawful.
“However, on Thursday night we unfortunately saw incidents of violence and aggression which have no place on our streets.
“We will deal robustly and quickly with anyone intent on coming into #Epping to commit selfish criminal behaviour.
“We will police impartially, without fear or favour, and have legal responsibilities to protect those who want to exercise their rights peacefully and we cannot prevent, hinder or restrict peaceful assembly.”
It comes after a man was charged with violent disorder and criminal damage on Sunday afternoon following previous clashes outside the hotel.
Eight police officers were injured after what started as a peaceful protest on Thursday evening.
Keith Silk, 33, of Torrington Drive, Loughton, was arrested on Saturday, Essex Police said.
The force said on Sunday that the CPS had authorised police to charge Silk with one count of violent disorder and one count of criminal damage.
He was remanded into custody and will appear at Chelmsford Magistrates' Court on Monday.
Thursday's demonstration was one of a series of protests outside the hotel since 38-year-old asylum seeker Hadush Gerberslasie Kebatu was charged with sexual assault after an incident where he is alleged to have attempted to kiss a 14-year-old girl.
He denied the charge when he appeared at Chelmsford Magistrates' Court on Thursday.
