Pilot dead after chopper crashes into Cairns hotel

A pilot has died in a fiery helicopter crash on the roof of a hotel in Australia. 

Emergency services rushed to the scene after reports the twin-engine chopper hit the DoubleTree by Hilton hotel in Cairns, far north Queensland, before 2am on Monday.

Police confirmed the pilot - the helicopter's sole occupant - died at the scene.

"Forensic investigations are under way to formally identify them," police said in a statement. 

The crash prompted police to declare a Public Safety Preservation Act, an exclusion zone encompassing the city's Esplanade and Minnie, Aplin and Grafton streets.

Propellers from the helicopter dislodged during the crash, with one landing on the main street outside the hotel and the other in the hotel pool, Queensland Ambulance Service said.

The crash resulted in a fire which prevented emergency crews entering immediately, Queensland Ambulance's Caitlin Denning said.

"At the time, it was too unsafe for us to enter the hotel to view the (impact site)," she told reporters.

She said there were frightening reports the impact sounded like an explosion.

"There were reports of it sounding like a bomb, and seeing the fire and smoke, a lot of the occupants of the hotel were unsure of the situation," Ms Denning said.

"There is a lot of unease here."

Between 300 and 400 people were evacuated from the site and taken to another hotel in Cairns' city centre.

Two hotel guests, a man in his 80s and a woman in her 70s, were taken to Cairns Hospital in a stable condition.

The exclusion zone remains in place and people are being warned to avoid the area.

Officers are on scene investigating the circumstances of the incident. 

The Australian Transport Safety Bureau is also deploying crash investigators to the scene.

"The ATSB will investigate a helicopter accident at a Cairns hotel early on Monday morning," the agency said in a statement.