Firefighters on Wednesday said one of the five people who died in a Jordan fire may have jumped from height while trying to escape to safety.

The blaze broke out just before 8am on the first and second floors of New Lucky House on Nathan Road, where guest houses and a gym were located, before spreading to other floors.

Lam Kin-kwan, a divisional commander from the Fire Services Department, said they would set up a team to look into the cause of the fire.

"We have found that some plastic boards and some electric wiring were installed at the lobby on the first floor. So it may be one of the reasons that caused the fire and also the smoke alongside the corridor as well as the staircase," he said.

Lam said firefighters evacuated 250 people from the building, while another 50 fled on their own.

A total of five people who had inhaled smoke or received burns were certified dead at the hospital.

Lam said one of them was found on the first floor canopy, and the others were found either in the corridor on the second floor or the staircase between the seventh and eighth floors.

Thirty-three other injured people were rushed to hospital.

Police said they would conduct a criminal investigation and collect evidence from the building later on Wednesday.

Jonathon Burnett, the police commander of the Yau Ma Tei division, said they would also assist tourists staying in the building.

"There are a large number of guest houses and villas up there... some of those people have actually got flights out of the territory [on Wednesday] back to their home countries. So we're doing all we can to facilitate them to get their luggage and to get on their planes," he said.

The No. 3 alarm fire was put out at 10:30am.