A massive fire blazed through a 27-storey apartment block in west London in the early hours of Wednesday, police and fire services said. London fire commissioner said there were some fatalities in the fire.
The fire brigade said 40 fire engines and 200 firefighters were called to the blaze in Grenfell Tower, which has 120 flats, on the Lancaster West Estate.
London ambulance service said 50 people had been taken to five hospitals after the high-rise fire.
"At this time I am very sad to confirm that there have been a number of fatalities, I cannot confirm the number at this time due to the size and complexity of this building," Dany Cotton, commissioner of the London fire brigade told reporters.
He said the structural engineer was monitoring the stability of the building, which appears safe for now. Cotton added that they were still looking for any remaining people inside the tower
block.
"Crews have only been as far as the 19 and 20 floors of tower block. We rescued a large number of people very early on across different floors," said the fire brigade commissioner.
London mayor Sadiq Khan said a "major incident" had been declared. He said questions will need to be answered over the safety of tower blocks following the deadly fire.
Some residents were seen using bedsheets to make their escape from the tower block. Witnesses could hear screaming from the upper floors as the flames rose and one desperate resident could be seen waving a white cloth.
Eyewitnesses said they had seen others fall or jump from the stricken building.
"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.