Man found alight outside Perth church

Perth detectives are investigating reports a man was set alight outside an inner city church.

Police say the 68-year-old suffered significant burns after he was approached by another man on Beaufort Street in Highgate around 5pm on Saturday.

Moments later he was on fire while the other man left the scene.

Police say a number of people assisted the victim, pouring water over him to extinguish the flames.

He was rushed to Fiona Stanley Hospital by St John Ambulance for treatment of burns to his face, upper body and hands.

Detectives say they want to speak to anyone who witnessed or has information regarding the incident.

According to 7NEWS, emergency crews descended on a soup kitchen outside the church after the man was doused in petrol and set alight.

A witness in the kitchen at the time told the network bystanders were able to bundle the man into a shower before ambulance officers got there.