Four men, believed to be members of far left and far right political groups, have been arrested after a brawl allegedly involving poles, bottles and fluorescent light tubes broke out at a Sydney service station.

Police said the fight started near the service station on Enmore Road, Newtown about 8:00pm after the men recognised each other from posts on social media.

When Newtown police arrived they found two men, aged 36 and 37, at the scene with minor injuries.

They were both taken to Royal Prince Alfred Hospital and were discharged this morning and then arrested.

Police also arrested two men, aged 21 and 23, at the scene.

The ABC understands one of the men was Daniel Evans, a prominent member of the nationalist group the United Patriot Front.

A statement on the group's Facebook page said the attack was politically motivated and that Evans was ambushed by members of the far left organisation Antifa.

Officers said the injured men are now helping the police with their inquiries.

Police said a crime scene has been established and investigations into the incident continue, with police appealing for any witnesses who have not yet come forward to contact Crime Stoppers.