At least 30 people taken to London hospitals after devastating fire (VIDEO)

LONDON — The London Ambulance service says 30 people have been taken to five hospitals after a massive fire at a high-rise apartment building in west London.

Ambulance officials say crews remain on scene as firefighters continue to battle the blaze in the 27-story building. It is not clear if people are trapped inside. Hours after the fire broke out, a plume of smoke can be seen from miles away.

The fire started around 1 a.m. London time and spread quickly through the building. More than 20 ambulance crews were on the scene, along with 200 firefighters and 45 fire engines.

Around 200 firefighters and 40 fire trucks were deployed to tackle the blaze, as rescue workers try to evacuate the building in Lancaster West Estate in North Kensington, London Fire Brigade said.

The fire broke out before daybreak local time Wednesday, when most of the building’s residents would have still been in bed.

“The whole building is on fire (and) spreading fast,” witness Goran Karimi told CNN.

He said he saw people jumping from the building.

The London Fire Brigade said the cause of the fire is still unknown. In a statement posted on Facebook, the service said the “fire is from the second floor to the top floor of the 27 floor building.”

“Firefighters wearing breathing apparatus are working extremely hard in very difficult conditions to tackle this fire. This is a large and very serious incident and we have deployed numerous resources and specialist appliances,” Assistant Commissioner Dan Daly said.

CNN producer Salma Abdelaziz, who is outside the apartment block, said it was a “terrifying scene.”

“Chunks of the building are falling off in flames,” she said, adding there is a “massive” swathe of fire across the side of the building.

The sounds of sirens and helicopters is non-stop as locals and residents, evacuated from the building, begin to gather outside to watch the blaze.

Residents told CNN they had seen people still trapped inside the building.

Grenfell Tower

The 27-story Grenfell Tower was built in the 1970s and recently subject to a $10.9 million redevelopment, according to property firm Rydon.

Close to Notting Hill, the tower block is around a five minute walk from the Latimer Road Underground station and near the Westfield shopping center in the west London suburbs.

According to property website RightMove, the average rent in the building is around $2,500 a month.