A man died and 10 people were injured in the fight between two groups of people at a park in Zillmere on Sunday afternoon.

Detective Superintendent Tony Fleming says police are concerned some of the people involved won’t cooperate with investigators and will take matters into their own hands.

“It’s a horrific, unacceptable attack in our society and I can only imagine that as a parent or a sibling that would cause angst in my mind if it was someone I loved,” he told reporters on Monday.

“But retribution is not going to solve the problem. We have seen that in societies around the world where it becomes tit for tat.”

Earlier, officers appealed for calm after friends and families of those hurt in the melee got into fights outside Royal Brisbane and Women’s Hospital, where the victims were being treated.

Flemming appealed for calm after officers broke up scuffles between friends and family members outside Royal Brisbane and Women’s Hospital where the victims were being treated.

“None of that behaviour is helpful to those who’ve been injured and nor to others that are using the hospital,” he told reporters on Monday morning.

It’s understood a group of people arrived at the park seeking to take “retribution” for another incident that happened in Brisbane’s west.

Flemming said a brawl erupted and police believe knives and baseball bats were used and glass bottles were thrown.

A man aged about 20 died and 10 other people were being treated for wounds and other injuries from the fight.

“It was dark, there were heightened emotions and we had a number of people critically injured,” Queensland Ambulance Service medical director Stephen Rashford said.

Police are still hunting a number of people who ran away when officers arrived at the scene. A police helicopter was unable to track them down.

A crime scene has been established and investigations are continuing with Det Supt Flemming urging witnesses to come forward.

“We are doing all we can to investigate this and hold people to account for the level of violence that occurred … but also we are active right across southeast Queensland now to try and ensure we don’t have further incidents,” he said.

“We believe knives and baseball bats were used in that attack,” Fleming said.

“We know at least one young man has died and there are about 10 other people who have been hospitalised as a result of that incident.

“Two of those people, I’m led to believe, are in a critical condition.

“I’m concerned this incident is the result of a retribution amongst these people for an incident that happened earlier this week in the western suburbs of Brisbane.”

Fleming said he was concerned there could be further violence.

“What we would ask is for the community to remain calm,” he said.

“We are doing all we can to investigate this and hold people to account for the level of violence that happened.

“We are active right across southeast Queensland now to ensure we don’t have a repeat of this.”

Fleming says police are now stationed at a number of hospitals.

“We have, as I have indicated, police both at the locations where we think there might be trouble but also on patrol to make sure — or do our very best to prevent — any escalation.”

He said it was still early on in a complex investigation.

“As I’m sure you can appreciate we’ve got a large number of people who’ve confronted each other … the outcome of that is one young man is dead and a number of people are very, very, seriously hurt.”

He urged witnesses to come forward.

“Both for justice, for those who’ve been injured, but more importantly to make sure that we don’t have any further trouble.”

The incident comes ahead of the state election, with the major parties already debating crime policies, and after reports of car-jackings in Brisbane. Liberal National Party leader Deb Frecklington today promised to recruit an extra 170 police for Brisbane, with new taskforces to focus on gang violence and car-jackings, arguing “Labor’s soft-on-crime approach is failing to protect the community”.

-AAP, additional reporting ABC, Sean Parnell