Three gardaí were injured and one person was arrested following disturbances in Coolock in Dublin last night.
One of the injured gardaí was taken to hospital for treatment for facial injuries.
A disused factory in the area went on fire last night following a protest against its use as accommodation for asylum seekers.
Two units Dublin Fire Brigade attended the fire and brought it under control.
It follows a fire at the same site on Thursday night, which gardaí are treating as suspected arson.
The Garda Public Order Unit was also deployed to the scene in Coolock.
Objects were thrown by protesters towards the Public Order Unit and pepper spray appeared to have been deployed by the gardaí.
A section of the Malahide Road in Coolock was closed in both directions.
Earlier, more than 1,000 people attended a protest outside the disused building on the Malahide Road in what was described by organisers as a peaceful meeting.
A number of speakers, including Councillor Glen Moore, delivered speeches outside the factory.
Crowds also heard from people who claimed they were pepper-sprayed during disturbances in the area on Monday night, while other speakers were critical of Garda Commissioner Drew Harris.
Another speaker said Ireland's sovereignty was under threat because of increased immigration and falling birth rates.
A number of motorists on the Malahide Road beeped their horns in support of the protest.
The crowd then marched towards the local garda station where they were met by a wall of gardaí.
Councillor Malachy Steenson read out a letter which was handed to gardaí in protest of what the group said were "heavy-handed tactics" employed by officers on Monday.
The protest then came to an end and the crowd mostly dispersed.
Earlier, Mr Steenson said the group 'Coolock Says No' organised the march, adding that it would be attended by a number of other such groups from around Dublin.
A garda helicopter circled overhead and close to 50 officers were on the ground.
People carried signs that read 'Irish Lives Matter' and 'The Irish People'.
Most of the crowd was made up of adults but there were also some families and children in attendance.
Early yesterday, the Taoiseach warned that anyone who engages in "thuggery" and breaks the law while taking part in protests at Coolock will "face the full rigour of the law".
Simon Harris also rejected criticism of the garda operation in Coolock after protesters carried out a second arson attack in a matter of days at the site, which is being renovated to accommodate more than 500 International Protection Applicants (IPAs).
Speaking after addressing the annual MacGill Summer School in Glenties in Co Donegal, the Taoiseach said everyone has the right to protest, but warned those who "cross the line".
He said there was a big difference between the local community of Coolock and those "looking to sow division, damage social cohesion and generally bring fear and mayhem to an area".
Mr Harris said: "I would always support the rights that people have to protest, but I have to say what we've seen in recent days has not been that, what we have seen in recent days has been an attempt by a relatively small number of people to engage in lawlessness, to engage in thuggery and to engage in criminal activity.
"I have a very clear understanding of the difference between protest and lawlessness, between protest and criminality.
"What I would say to everybody in this country, it's very important everybody does too, because if you engage in protest, you will be fully protected by the law, if you engage in lawlessness, if you cross the line and you engage in thuggery, you will meet the full rigors of the law."
Read more: Investigation into suspected arson attack at Coolock site earmarked for asylum seekers
Asked if he was concerned that protestors had been able to mount another attack at Coolock last night despite the site being the focus of protest and violence earlier in the week, Mr Harris defended the gardaí.
He said: "What I really won't kind of accept in any manner or means is when people engage in lawlessness, the first kind of line of questioning being did the gardaí do their job?
"I'm extremely proud of the job done by the men and women of An Garda Síochána, people who put themselves in harm's way while others threw bricks at them, lit fires, threw petrol bombs."
Additional reporting Vincent Kearney, Gavin O'Callaghan
