At least 30 people were taken to hospital on Wednesday after a fire engulfed a 27-storey block of flats in central London, the ambulance service said.
"We can confirm that we have taken 30 patients to five hospitals," London Ambulance Service said.
The fire engulfed at Grenfell Tower on Latimer Road in Lancaster West Estate in West London, with several people feared trapped.
"Officers, the London Fire Brigade and the London Ambulance Service are currently at the scene. An evacuation process is underway," said the Metropolitan Police.
The fire brigade said they were responding to a fire on the Lancaster West Estate. "40 fire engines & 200 firefighters have been called to the Lancaster West Estate tower block fire #NorthKensington," Fire Brigade tweeted.
"Crews continue to work hard at tower block. Fire is from 2nd to top floor of 27 storey building," it added.
According to several tweets, people were screaming for help.
"It has burned through to its very core. It looks very bad, very very bad. I've never seen anything like this. It's just such a big fire. The whole building is just crumbling. It's just billowing black smoke," an eyewitness told the BBC.
(More details are awaited)