At least six people are dead after a huge fire raged through the night at a west London tower block. Photo: BBC News

Eyewitnesses described people trapped in the burning Grenfell Tower, in north Kensington, screaming for help and yelling for their children to be saved.

Firefighters rescued many people and are still trying to put the fire out in the 24-storey block 12 hours on.

Police say there may still be people in the building who are unaccounted for.

During the night, eyewitnesses said they saw lights - thought to be mobile phones or torches - flashing at the top of the block of flats, and trapped residents coming to their windows - some holding children.

It is understood that "several hundred" people would have been in the block when the fire broke out shortly after midnight, most of them sleeping.

 Commander Stuart Cundy, of the Metropolitan Police, said the recovery operation would be "complex and lengthy", and the number of fatalities was expected to rise.

He declined to give any details of the number of people who may be missing.

He said it was likely to be some time before police could identify the victims, adding that it was too early to speculate on the cause of the fire.

An emergency number has been set up on 0800 0961 233 for anyone concerned about friends or family.

More than 70 people have received treatment in hospital. At least 20 are known to be in a critical condition.

By mid-morning, the building looked to be just smoking ruins but the fire has again taken hold, and cladding is falling to the ground.

Prime Minister Theresa May is "deeply saddened by the tragic loss of life", said Downing Street.