Hero Deliveroo driver speaks out after defending a young girl from a knife attack.
A knife attack that injured five people, including three young children, in Dublin on Thursday has sparked anti-immigration riots in the city centre.
The scene was still sealed off shortly before 6pm when a group of about 50 anti-immigrant protesters briefly broke through a police barrier.
Some shouted "get them out" and one kicked off the wing mirror a police car.
Another was draped in an Irish flag.
A larger crowd then began throwing objects and fireworks at riot police when they arrived, and the rioting broke out of control.
A hotel housing migrants was also attacked.
The crowds began to disperse around 9pm.
Police would not comment on the nationality of the man in custody.
Police Commissioner Drew Harris said all lines of inquiry related to the knife attack remained open.
That contradicted a senior officer who earlier told reporters that police were satisfied the incident was not related to terrorism.
"I'm not going to speculate any further in respect of a terrorist motive," Mr Harris said. "Until we're sure what the motive is, we have to keep an open mind as to why this happened."
Net migration among Ireland's 5.3 million population rose to its second-highest level since records began in the 12 months to April.
And about 100,000 Ukrainian refugees have arrived since Russia's invasion, among the highest per capita in the EU.
Ireland’s Justice Minister, Helen McEntee, described the rioters as “thugs”.
“I want to see people in prison here because these are acts of thuggery, these are criminal acts," Ms McEntee said.
She said members of Ireland’s police service An Garda Siochana are “responding with force”.
Anybody who attacks a garda or emergency workers faces up to 12 years in prison under recent legislation, Ms McEntee said.
Asked if the riot was the fallout of the garda’s strategy for far-right protests, she said: “This is not about immigration, this is not about a particular group of people wanting to make a clear message or a point.
“This is about a group of thugs who are using this really horrific act today as nothing but an opportunity to come in and wreak havoc.”
Children receive emergency medical treatment
A girl, 5, was receiving emergency treatment after sustaining serious injuries in the stabbing.
A man in his late 40s, also being treated for serious injuries, was arrested by police who said they are not looking for any other suspect.
Police said it appeared the man attacked a number of people on Dublin's Parnell Square shortly after 1.30pm. Members of the public intervened quickly.
A woman in her 30s was also being treated for serious injuries while the two other children, a five-year-old boy and six-year-old girl, suffered less serious injuries.
The boy has been discharged from hospital.
Chaos in city centre
Public transport was suspended and patients advised not to travel to a nearby maternity hospital unless absolutely necessary after clashes between riot police and protesters.
The demonstrators arrived at the scene of the attack beside the main thoroughfare of O'Connell Street.
A double-decker bus was burnt to the ground in front of the Daniel O'Connell statue at the head of the street, and windows were smashed at a nearby hotel and restaurant.
A clothing shop was looted and a police car was burnt out.
"They are disgraceful scenes," Mr Harris said after sending 400 officers to restore public order.
"We have a complete lunatic, hooligan faction driven by far-right ideology engaged in serious violence."
Such rioting is almost unprecedented in Dublin.
There are no far-right parties or politicians elected to parliament, but small anti-immigrant protests have grown in the past year.
The government is reviewing security around parliament after a recent protest trapped members inside.
