Fire engulfed a 24-story government-owned apartment building near Notting Hill in west London in the wee hours of Wednesday, killing at least 6 people and injuring 74, police and fire services said.

Flames could be seen racing through the building after the fire started at about 12:54 am. More than 250 firefighters fought the blaze through the night.

Police confirmed the fatalities but said the death toll is likely to rise as firefighters search the building fully in the next few days.

London Fire Commissioner Dany Cotton said she had never seen anything like it in her 29 years of experience. "This is a major fire that has affected all floors ... from the second floor upward," she said.

Eyewitnesses told China Daily that they heard screaming and people calling for help. Majid Mahdi said: "I live next door. I ran to help, we could hear people screaming and crying for help. The fire just got bigger and bigger. It has been a very sad night."

Dani Smith, who lives in a neighboring building, called it an inferno. "There have been fatalities, families, children and old people. Everyone's been evacuated. We were in the block right next to it. I've been told it could take up to three days before we can get back in because the block next door could be unsafe."

Local residents said the building, with 120 apartments, had recently been refurbished. The cause of the fire was unknown.

London Mayor Sadiq Khan declared a major incident and London ambulance officials said they had taken 50 people to five hospitals. Paramedics treated others at the scene.

The building, built in 1974, is owned by the Royal Borough of Kensington and Chelsea in London and managed by a company under contract. The renovation in 2014 cost 10 million pounds ($12.74 million) and followed complaints by residents of faulty wiring, poor ventilation and blocked fire exits.

The fire has dominated the news and may also set back announcement of a deal between the Conservatives and the Northern Irish Democratic Unionist Party on managing the government, the BBC reported. DUP sources said the fire made any announcement on Wednesday inappropriate.

Kevin Wang in London contributed to this story.

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