An off-duty paramedic has been bashed at Windang while on a charity bike ride.
Daniel Mansbridge was just 7km into the ride when he was "shoulder charged" by a pedestrian on Windang Bridge on Friday.
Mr Mansbridge was then set upon by the attacker and at least two others who were underneath the bridge and severly beaten.
He suffered severe injuries to his eye that require surgery once the swelling and bruising subsides.
Mr Mansbridge is at home recovering.
Ambulance NSW duty operations manager for the Illawarra Norm Rees appealed for any witnesses to the assault on Friday to contact police.
"Our paramedic was out on a ride to raise funds for kids and this guy shoulder charged and him knocked him of his bike," Mr Rees said.
"Because he turned around to ask what it was all about he got beaten up in a bad way.
"We hope anyone who saw this or know the people will come forward. This is not good enough, we need these people charged," he said.
"We are out there every day saving people and these mugs decide it's alright to bash him. They wouldnt know he's a paramedic but that doesn't matter."
Mr Mansbridge's mother Mary made a plea on Facebook for witnesses to come forward.
She posted pictures of her son's injuries, sayind "the result of the thugs that were hanging around Windang bridge ... and pushed Dan off his bike and when he got up and chased him".
"At least 3 of them beat him up!!!!....scum of the earth...their parents need to know what their sons do for fun.
"I hope someone saw this as the police want to find them ... older teenagers around 15-16 .... I hope they are caught and made to be accountable for their actions..what started as a stupid prank jumping out in front of Dan leading to him ... going head over heels bike and all."
Mrs Mansbridge said the result was a paramedic who saves lives "being left beaten and injured including fractured eye socket needing surgery".
"He's going to be out of action and off work for a long time..I hope anyone that can help will give information to the police.
"This is not right ... if you saw anything or know the incident please contact police."
Mr Rees said the type of assault was what caused PTSD and long term issues for victims and should not be tolerated or accepted by the community.