NEW YORK, United States-- At least 19 people have died and dozens are injured after a fire tore through a high-rise apartment building in the New York borough of the Bronx, Mayor Eric Adams said Sunday.

US media reported that several children were among the dead.

"We know that we have 19 people who are confirmed dead, as well as several others in critical condition," Adams, who has been mayor for barely over a week, told CNN, adding that 63 people had been injured.

"This is going to be one of the worst fires in our history," he said.

The injured were taken to five hospitals; many suffered from cardiac and respiratory arrest, the New York Times reported.

The blaze comes just four days after a fire in Philadelphia killed 12 people, including eight children, in a three-story public housing building in what was one of the deadliest recent fires in the United States.

In New York, there were fears of a growing toll.

"The last time we had a loss of life that may be this horrific was a fire which was over 30 years ago, also here in the Bronx," said Fire Marshal Dan Nigro, quoted by NBC News.

At least 200 firefighters responded to the blaze, which broke out mid-morning on the second and third floors of a 19-story building on East 181st Street, several blocks west of the Bronx Zoo.

Flames quickly engulfed much of the structure, and Nigro said the smoke was so dense as to be "unprecedented."

Photographs and video posted on social media showed flames and thick black smoke billowing out of a third-story window of the brick building as firefighters operated on a nearby ladder.

The cause of the fire was not immediately clear.