Irish police say five people, including three young children, have been taken to hospital following what local media say was a stabbing in Dublin city centre.

Prime Minister Leo Varadkar said on Friday morning (AEDT) that police had detained a suspect.

Broadcaster RTE quoted a witness on the scene as saying she saw a man in a “stabbing motion” from across the road and that when she ran closer, she said that two children had been stabbed as far as she could tell.

Anthony Boyle, 31, an IT consultant who lives on the road and was passing by told Reuters, “I saw a child on the ground, a little girl”.

“There was complete and utter pandemonium, women wailing, men screaming and crying.”

Boyle said he saw a man lying on his side but did not see what led up to that.

One girl had sustained serious injuries and the other two children were being treated for less serious injuries, police said.

A woman is also being treated for serious injuries and a man has less serious injuries.

Local media reported that the people were stabbed on Dublin’s Parnell Square, which is next to Dublin city’s main thoroughfare of O’Connell Street.

There were about 20 officers on the scene, which police said remained sealed off.

“We are all shocked by the incident which has taken place in Parnell Square,” Varadkar said.

The Irish Times reported that the detained suspect had sustained wounds believed to be self-inflicted. It said early indications suggested a man tried to attack some young people and that passers-by intervened.

The motive for the attack, which was close to a school on the street, had not been established, the paper said.

Irish Justice Minister Helen McEntee said violent disorder that had erupted in Dublin after the stabbing attack would not be tolerated as she blamed a “thuggish and manipulative element” attempting to sow division.

-AAP