Hundreds of people are trapped on the roof of a skyscraper in Hong Kong following a fire according to media reports.

Wednesday’s blaze at the 38-story World Trade Centre in Causeway Bay triggered a large response, with firefighters trying to rescue several using emergency ladders. Dozens of people have already been evacuated.

The South China Morning Post newspaper (SCMP) said more than 300 people were trapped on the building’s rooftop, and at least 12 people – including a woman in her 60s – suffered from smoke inhalation.

Four of them were hospitalised, SCMP added.

It said the fire broke out at 12:37pm local time (04:37 GMT) in an electrical switch room before ripping through the scaffolding of the building, which houses both offices and a shopping centre.

Citizen News, citing a police officer at the scene, put the number of people trapped on the rooftop at 350 and said another 100 people were waiting to be rescued on a platform on the fifth floor of the building.

As of 3:06pm local time, authorities said the fire was under control.

The fire was upgraded to a level three incident, according to a police notice.

Fires are graded on a scale of one to five, with five being the most severe.

Firefighters have mobilised two breathing apparatus teams and two water jets to help fight the fire, police said.