A baby is among at least 12 people who have been killed in a fire at an apartment building in New York City.
Other residents are in a critical condition after a blaze New York fire commissioner Daniel Nigro described as "historic in its magnitude" broke out at around 7pm on Thursday local time.
More than 160 firefighters were called to the five-storey building near Bronx Zoo and worked to extinguish the fire in freezing conditions, with water sprayed from hoses turning to ice on the street.
Mayor Bill De Blasio said the blaze would "rank as one of the worst losses of life to a fire in many, many years", having already eclipsed the death toll of another fire in the Bronx in 2007, which killed nine children and an adult.
Excluding the 9/11 terror attacks, it was the worst fire in the city since 87 people were killed at a social club fire – also in the Bronx – in 1990.
Mr De Blasio later tweeted his thanks to the New York Fire Department "for their bravery and quick action".
He continued: "I want to offer my prayers to all the families who have lost their loved ones this evening or who are struggling. I ask all New Yorkers to keep them in your prayers, too.
"Tonight in the Bronx we've seen the worst fire tragedy in at least a quarter of a century. It is an unspeakable tragedy, and families have been torn apart."
Mr Nigro added: "We may lose others as well. Our hearts go out to every person who lost a loved one here and everyone who is fighting for their lives.
"In a department that's certainly no stranger to tragedy, we're shocked at this loss."
Tonight in the Bronx we've seen the worst fire tragedy in at least a quarter of a century. It is an unspeakable tragedy, and families have been torn apart. pic.twitter.com/0kCFMzxt79
— Bill de Blasio (@NYCMayor) December 29, 2017
Windows on some upper floors were smashed and blackened as the flames ripped through the building, which according to city records did not have an elevator.
Neighbourhood resident Robert Gonzalez, who has a friend who lives in the building, said she got out on a fire escape as another resident fled with five children.
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Another local, Jamal Flicker, told the New York Post: "The smoke was crazy, people screaming, 'get out!' I heard a woman yelling, 'we're trapped, help!'."
The cause of the fire is not yet known.