Pictures: New York subways disrupted as more heavy rain triggers flooding

Torrential downpours after a week of mostly steady rainfall triggered flash flooding in New York City on Friday, disrupting subway service in the country's most populous city and turning many of its streets into small lakes.

A flash flood warning went into effect for New York City until midday as more than 2 inches (5.08 cm) of rain fell in some locations by Friday morning and 3 more inches possible within hours, the National WS eather Service said.

As much as 6 inches of rain fell in some locations, including Brooklyn, lower Manhattan and John F. Kennedy International Airport in the borough of Queens, said Zack Taylor a meteorologist with the National Weather Service's Weather Prediction Center in College Park, Maryland.

"More rain is falling," Taylor said. "This is seriously a life-threatening situation." He warned against travel at until the weather system pulls away from the coast later on Friday evening.

The extreme rainfall prompted New York Governor Kathy declared a state of emergency for New York City, Long Island, and the Hudson Valley.

"Please take steps to stay safe and remember to never attempt to travel on flooded roads," the governor said in a message posted on the X social media platform.

Flooding caused major disruptions to New York's subway system and the Metro North commuter rail service, according to the Metropolitan Transportation Agency. Some subway lines were suspended entirely, including the G, which connects Brooklyn and Queens, and many stations were closed.

Some 18 million people in the New York metropolitan area and in other major cities along the East Coast were under flood warnings, watches and advisories from the weather service.

Photographs and video footage from across the New York area showed flood water submerging vehicles on neighbourhood streets and water drenching the inside of subways stations, disrupting morning traffic for millions of commuters.

In low-lying Hoboken, a New Jersey city directly across the Hudson River from lower Manhattan, all but one of the southern routes into town were under water. The city's newly installed flood gates, designed to close automatically when water pooled on roadways, were down, blocking many streets to vehicle traffic.