Police were called to Leichhardt Oval in Sydney's Inner West on Sunday night after a violent brawl erupted outside the ground, shocking onlookers, including families, who attended the Australia Cup soccer match.
Dozens wearing masks were seen throwing flares and rocks at each other following the match between Sydney FC and the Central Coast Mariners.
In a video shared on Twitter by veteran sports journalist Ray Gatt, an angry mob can be seen dispersed on the street outside the stadium shouting and waving flares.
"Drama at the end of the Australia Cup game at Leichhardt. Bloody idiots," he wrote.
Mr Gatt claimed the brawlers were not Central Coast or Sydney FC fans, implying it wasn't a fight between rival clubs. He said they were not inside the ground at any stage.
Those involved can be heard hurling abuse at other fans. The flares were being carelessly thrown, narrowing missing nearby cars.
Traffic barriers and poles were also being launched across the pavement by angry revellers. It's not known if anyone was injured during the incident.
Security guards wearing yellow vests were present at the scene but the video shows them appearing to keep a safe distance from the offenders.
Families in fear as brawl erupts at Leichhardt
At the end of the video, innocent bystanders were scene getting caught up in the chaos while attempting to stay out of harm's way.
Mr Gatt described the people in the video as "idiots" and "morons".
"Parents who had their kids at the game were fearful as they tried to exit the ground," he claimed.
Posting on the video, one person said he was at the game with his wife and their two-year-old daughter.
"Walking out they threw a flare 2m away from us," he claimed. "Security were watching or running away."
Officers from Leichhardt Police Area Command attended the scene at around 7:30pm, NSW Police said in a statement.
The Public Order and Riot Squad (PORS) also attended and the crowd started to disperse, they said.
"An investigation into the circumstances surrounding the incident has commenced, and inquiries continue to identify those involved," NSW Police said.
Detective Chief Inspector Grant Watson said the force is "incredibly disappointed with what happened."
"Leichhardt Oval is predominantly family-friendly place, and what we saw was incredibly dangerous and reckless," he told media on Monday.
"Throwing flares can cause serious injuries. There were a lot of children and families there."
Insp Watson confirmed the mob didn't attend the football match. No arrests have been made.
Any witnesses or anyone with information is urged to contact Crime Stoppers on 1800 333 000.
Yahoo News Australia has contacted Sydney FC for comment.
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