Eight people have been granted police bail over a "serious disturbance" in a Gwynedd town which left three people in hospital.
Six males aged 15 to 19 and two women aged 20 and 21 were held following the incident by a play area in Dolgellau early on Saturday.
A 21-year-old man in intensive care at Swansea's Morriston Hospital has since been taken off the critical list but has serious facial injuries.
All eight were bailed for a week.
The two other injured men, including a 19-year-old man, were taken to Ysbyty Gwynedd in Bangor and were released on Sunday.
The seriously injured man, who was initially taken to hospital in Aberystwyth, is to undergo surgery on an eye socket, police said.
Officers are continuing to investigate the incident, which happened at about 0200BST on Saturday near Dolgellau leisure centre.
Inspector Meirion Ellis from North Wales Police, who is leading the investigation, said: "It's very unusual to have such serious injuries.
"It's been quite a nasty incident and we are appealing for anybody with any knowledge of the incident or any information that can help the police (to come forward)."
He added that the investigation is still at an early stage and officers are trying to piece together exactly what happened.
Mayor Delwyn Evans said that serious disorder on this scale does not happen often in Dolgellau.
People in the town are shocked, he said.
"This is something that has stunned the town of Dolgellau because this is an unusual happening.
"It's a very rare incident, the last time it happened was years ago.
"There is a good partnership between the police, the councillors and the people of Dolgellau and the park authorities have made things easier for the people of Dolgellau to enjoy themselves in the evening.
Mr Evans added: "Whoever knows anything about this should go back to the police, and give them the information they need."