Three young children were among five injured in a knife attack in Dublin on Thursday that sparked unrest in the city center and police have not yet ruled out a motive, including whether it could be terrorism-related, Reuters reported.

Public transport was suspended and patients were advised not to travel to a nearby maternity hospital unless absolutely necessary after clashes between police and anti-immigrant protesters who arrived at the scene of the attack near the main thoroughfare, O’Connell Street.

• Read also: Ireland: five people, including three children, hospitalized after a knife attack in Dublin / “Motives are not ruled out” / Police do not reveal the identity of the attacker

Small-scale anti-immigrant protests have grown over the past year

A double-decker bus was burned to the ground in front of the Daniel O’Connell statue at the end of the street, and the windows of the nearby Holiday Inn and McDonalds restaurants were smashed. The Footlocker store was robbed.

“These are shameful scenes. We are dealing with a group of absolutely deranged hooligans, driven by a far-right ideology, who have committed serious violence,” Police Commissioner Drew Harris told reporters after deploying 400 officers to restore public order.

A police car was also set on fire.

There were almost no such riots in Dublin. There are no far-right parties or politicians elected to parliament, but small anti-immigrant protests have gained momentum over the past year. The government is reviewing security measures around parliament after recent protests locked lawmakers inside.

All assumptions remain

Harris said all lines of inquiry into the attack remain open, contradicting a senior officer who previously told reporters that police were confident the incident was not terrorism-related.

“I am not going to think about the terrorist motive any further. Until we’re sure what the cause is, we have to keep an open mind as to why it happened,” he said.

A five-year-old girl received emergency treatment after being seriously injured in a stabbing. A 40-year-old man, who was also seriously injured, was detained by police, who said they were not looking for other suspects.

Police said the man appeared to have attacked several people in Parnell Square in Dublin shortly after 13:30 GMT. Bystanders intervened early in the attack.

A 30-year-old woman was also seriously injured, two other children, a five-year-old boy and a six-year-old girl, received minor injuries. The boy was discharged from the hospital.

The law enforcement officers did not want to disclose the nationality of the detainee

The scene was still cordoned off shortly before 6pm GMT when a group of around 50 anti-immigrant protesters briefly broke through a police barrier. Some shouted “get them out” and one kicked the rear-view mirror of a police car. Another was covered in an Irish flag.

A larger crowd then began throwing objects and shooting flares at police wearing helmets and shields as they were deployed and the riots spiraled out of control.

The crowd began to disperse around 21:00 GMT.

The law enforcement officers did not want to disclose the nationality of the detainee.

Net migration among Ireland’s 5.3 million residents rose to its second highest level since records began in the 12 months to April.

After the Russian invasion, around 100,000 Ukrainian refugees arrived, one of the highest per capita figures in the EU.

“There is a group of people, hooligans, criminals who are using this horrific attack to sow division,” Justice Minister Helen McEntee told reporters.

“Gardai (police) are using all possible forces to restore order. This will not be allowed,” the official added.