Police have charged two men with attempted murder as part of their investigations into an assault in Cardiff's Bute Park on Tuesday.
A 54-year-old man remains in a life-threatening condition at the University Hospital of Wales, South Wales Police said.
Jason Edwards, 25, and Lee William Strickland, 36, both from Cardiff, have been remanded in custody to appear at Cardiff Magistrates' Court on Monday.
Police are also looking appealing for help in finding a third suspect, an unknown female.
Detective Inspector Stuart Wales said: "This serious assault has caused understandable concern locally, and we want to reassure the public that a significant number of enquiries are ongoing.
"We will be relentless in identifying and bringing to justice anyone involved in this violent attack.
"The charging of these two men demonstrates that we are making significant progress and I’d like to thank the public for their support which has enabled this.
"I’d urge them to continue doing so, reporting any information – no matter how insignificant it may seem – to us.
"I’d also appeal directly to the female suspected of being involved in this incident to come forward voluntarily, as it is only a matter of time before we identify and locate her."
The incident happened at around 1am on Tuesday near the Sophia Gardens entrance to the park.
South Wales Police said a Major Incident Room was continuing to operate at Cardiff Central Police Station and that patrols have been increased in the area.
Anyone with information is asked to contact police.