Twin brothers have been seriously injured after they were ambushed by nearly a dozen youths at a park in Melbourne's west.
The 15-year-olds were lured to a park off Garretty Road in Caroline Springs about 5.40pm on December 30, after a social media post sparked an online argument, police said.
Police believe at least one of the attackers was armed with a machete.
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"It was meant to be a one-on-one type of fight over the social media post, however on their arrival they were ambushed by 11 individuals," Victoria Police Detective Constable Daniel Rankin said.
One of the victims jumped into a lake to escape the group, while his brother was slashed with a machete three times.
"The boys have ended up on the ground. One of them had their head stomped on. One of them had multiple lacerations to both arms," Rankin said.
One of the victims was only released from hospital yesterday and is likely to have lifelong injuries.
"The one with the slash wounds, his day-to-day life has been impacted during his recovery," Rankin said.
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"He's requiring the assistance of his family to do day-to-day activities."
The offenders, who are believed to be about 15 to 18 years old, fled before police arrived.
Police believe that before the attack, seven of the attackers parked at Boathouse Drive in a black Ford Ranger bearing the false registration DRY685.
Eight of them crammed back into the Ranger to flee the scene, police said.
"I s--- myself. Sorry for the expression, but this is getting bad, really bad," local Franca Esposito said.
"I'm scared now. I don't even open the door. I lock everything."
Detectives believe a video of the ambush is circulating online and are urging anyone who comes across the vision to report it.
"There's no justification for any of this sort of violence, and police will hold these offenders to account," Rankin said.
"It's a brazen, cowardly attack."
Police have released an image of the group and of the car, and particularly urge anybody who may recognise the distinctive clothing worn by some of the youths, to come forward.
Anybody with information is urged to contact Crime Stoppers online or on 1800 333 000.
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