Police are searching for a group of youths who bashed an autistic teenager in a park in Sydney’s inner west.

Ben Lawrence, 15, was trying to make friends when he was set upon by seven youths at Camdenville Park in St Peters last night. His only crime was attempting to talk to them.

“I got a rather urgent phone call at 8.30pm where he was terribly distressed. I’m bleeding, Dad. I’m bleeding all over my face,” his father Matthew Lawrence told 7NEWS.

Lawrence found his teenage son beaten and bloodied.

“They gave me almost a black eye. They hurt my nose. They hurt my lips,” Ben said.

Paramedics treated Ben’s injuries at the scene. Now Lawrence wants to know who attacked his son.

“No one deserves to be treated badly,” he said.

Police were called to Camdenville Park at St Peters and found up to 100 teens gathered. Witnesses say most fled when officers arrived about 8.45pm.

While locals welcome the multi-million-dollar revamp of the park, they say it’s also attracted trouble.

Residents are now calling for security cameras to be installed, hoping that will make the area safer.

“They’re not that expensive and it’s very easy. Put them up high and yeah, it’s really not that expensive,” one local said.

“If they spend money on this, they can spend money on that.”

“If something happens, you can find out what’s going on,” another local said.