A man and two police officers have been injured in an explosion at an apartment complex in Coffs Harbour on the New South Wales north coast overnight.

A 32-year-old male officer and a 23-year-old female officer were called to an apartment complex on Orlando Street in the Jetty tourist area about 7pm yesterday.

The pair found a 64-year-old man who had poured accelerant, believed to be petrol, over himself, officers said.

Police said he lit the fuel shortly after their arrival and there was an explosion that shattered windows and a door.

The 64-year-old was seriously injured and was taken to Coffs Harbour Hospital for treatment for a number of injuries before being transferred to Sydney's Royal North Shore Hospital burns unit.

The two officers have minor injuries, mainly from shattered glass.

A police critical incident team launched an investigation into the events leading up to the explosion.

Police have appealed for witnesses to come forward and have urged anyone with information to contact Crime Stoppers.

Officers said there were no suspicious circumstances.