There was disorder in Northern Ireland for the fourth night in a row but at a lower level than seen earlier this week.

In Portadown, County Armagh, on Thursday a crowd pulled bricks and masonry from a derelict building which they threw at police.

During the first three days of violence, which began in Ballymena, 41 officers were injured. Fifteen people have been arrested so far.

The disorder started on Monday after a peaceful protest over an alleged sexual assault in the County Antrim town.

In Portadown, police put out a warning on loudspeakers that they would fire baton rounds if the crowd did not disperse.

There was a heavy police presence in the centre of Portadown where around 400 protesters gathered on Thursday evening.

More than 20 police vehicles were parked along the main street and officers in riot gear blocked a number of roads.

There was a peaceful protest earlier in the town but some disturbances developed, with masonry, including an empty beer keg, being thrown at police.

A police helicopter also hovered over the town centre and officers had to extinguish a number of fires.

Democratic Unionist Party (DUP) MLA Jonathan Buckley called for “calm”.

He said: “Nobody wants to see violence on our streets no matter where they come from in Northern Ireland. The scenes over the past few days have been disturbing.”

Earlier, a housing association warned its residents to leave their homes and take measures to protect their properties ahead of the protest.

Meanwhile in Ballymena, there was also a police presence, mainly in the Clonavon Terrace area, with a number of landrovers parked at locations where there had previously been trouble.

However, after three nights of violent disorder, the rioters stayed away.

On Thursday evening, around 100 people turned up at an anti-racism protest in west Belfast. Members of the Northern Ireland Public Service Alliance (NIPSA) trade union and representatives from People Before Profit addressed the crowd.

Also there, were a number of people wearing black face coverings.

It passed off peacefully.

In a press conference on Thursday afternoon, the Police Service of Northern Ireland (PSNI) Chief Constable said families hid in attics and wardrobes during violent disorder in Ballymena this week.

Jon Boutcher described the violence as “racist”, adding “the people who are threatening families who are different to them – that is racism”.

Mr Boutcher said after a peaceful protest was “hijacked” on Monday evening, police and the fire service had to help families “who have done nothing wrong”.

He added that: “We stand absolutely shoulder to shoulder with the diverse communities in Northern Ireland.

“These bigots and racists will not win the day.”

The first protest was organised hours after two teenage boys appeared before Coleraine Magistrates’ Court.

They spoke through an interpreter in Romanian to confirm their names and ages. Their solicitor said they would be denying the charges.

Mr Boutcher said in addition to the two teenagers who have been arrested and charged, there was “a third suspect who is currently outside the jurisdiction”.

“We will be bringing him back into the jurisdiction,” he added.

Mr Boutcher said the family of the young girl wanted the violence to stop.

“She’s been further traumatised by what has happened over the last three nights,” he said.

Police have described the disorder as “racist thuggery, pure and simple” and targeted at ethnic minorities and law enforcement.

Over the three days in Ballymena, police officers came under sustained attack with petrol bombs, heavy masonry, bricks and fireworks thrown in their direction.

Mr Boutcher called on those involved to stop and warned there would be prosecutions.

“Don’t come out onto the streets tonight. If you do we will police you, and we will deal with you through the criminal justice system.

“We’ll be releasing images of those responsible. We will be going after them.”

He said that three young people were in court in Ballymena on Thursday and remanded into custody for “these disturbances”.

Jody Esguerra is an outreach worker for the Filipino community and has been helping others find somewhere safe to stay.

He said he received reports of a family that was “stuck inside” their home with “mobs and protesters” trying to enter, while “smashing the windows and throwing projectiles”.

“They’re scared for their lives”, he said, and added that they don’t feel “welcome” anymore.

He said the family “didn’t expect any of this to happen”.

They were woken up by “loud noises” and realised people were “throwing rocks at their door… and all tried to hide”.

The Social Democrat and Labour Party (SDLP) leader Claire Hanna described the scenes in Ballymena over the past few days as “dystopian”.

“It was one of the most disturbing things I’ve seen in this very, very challenged place,” she said.

Mukesh Sharma, the chair of the Northern Ireland Policing Board, said: “This violence is racism – pure and simple.”

He said: “It is hard to find the words to describe the scenes of vitriol and hatred on our streets,” adding that it is “mindless violence that is simply wrecking communities”.

“This violence needs to stop before a life is lost or serious injuries sustained.”

On Wednesday, the PSNI confirmed that a significant number of extra police officers were being deployed into areas affected.

Police Scotland has agreed to send officers, after police in Northern Ireland requested extra support under mutual aid arrangements.

In Larne, masked youths attacked a leisure centre and set it on fire on Wednesday.

The centre had been providing emergency shelter for families following the clashes earlier in the week, the council said.

There have also been incidents in Carrickfergus, Coleraine, north Belfast and Newtownabbey.

Olympic swimmer Danielle Hill, who competed in both the Paris and Tokyo Games, was at the facility when the attacks took place.

She took the decision to cancel swimming lessons after spotting four masked men near the centre.

The 25-year-old said: “I mean, it’s sad. It’s awful. I lay awake last night. When there’s kids involved it’s upsetting.

“It shouldn’t be happening. There was no need for the violence.”

In a statement, a council spokesperson said they were “assessing the significant damage” and that “the centre remains closed”.