Media playback is unsupported on your device Media caption A building in Minneapolis which had been ablaze was 'frozen' by fire hoses

The north-eastern US has been hit by a major winter storm, with 53cm (21 inches) of snowfall recorded in one town in Massachusetts.

Thousands of flights have been cancelled as heavy snowfall moved eastward from the Midwestern states.

The New York and New Jersey governors have declared a state of emergency, urging people to stay indoors.

Many schools and businesses have closed amid warnings the storm will worsen overnight and into Friday morning.

We are focused like a laser on protecting this city Bill de Blasio, New York City Mayor

"We're going to see a lot of snow and a lot of wind," said Jason Tuell, of the US National Weather Service. "We're concerned about whiteout conditions possibly tonight with the blowing and drifting snow."

More than 2,200 flights were cancelled on Thursday, and by the early hours of Friday a further 1,000 flights scheduled for later in the day had already been cancelled, according to FlightAware.com.

Outreach teams were working to get homeless people off the streets in New York City and Boston.

'Serious situation'

Late on Thursday evening, the National Weather Service said unofficial observations had recorded 53cm of snow in Boxford, north of Boston. Other areas of Massachusetts as well as New York experienced similar falls.

Similar accumulations were also expected in parts of the states of Vermont, New Hampshire and Maine, where many residents were recently without electricity because of an ice storm.

Image copyright Reuters Image caption People have been enjoying the snow in New York, but officials are urging residents to stay indoors as the weather worsens.

Image copyright AP Image caption It is a similar situation in Boston. These tubers enjoyed the snow in Boston Red Sox's Fenway Park on Thursday.

Image copyright AP Image caption Cars covered with snow at Chicago's O'Hare International Airport, which saw major delays and cancellations because of the storm.

Image copyright AP Image caption The state of Michigan saw up to 25cm (10 inches) of snow fall.

Image copyright Reuters Image caption Snowflakes collect on a car window in Massachusetts.

Weather officials have issued a blizzard warning for the Long Island region of New York, where up to 10in of snow is expected.

Some schools have already announced closures for Friday and New York Governor Andrew Cuomo ordered three major highways to close overnight.

The storm is expected to be an early test for New York City Mayor Bill de Blasio, who was sworn in on Wednesday. He had criticised his predecessor, Michael Bloomberg's response to a similar storm in late 2010.

"We are focused like a laser on protecting this city and getting everyone ready," Mr de Blasio said. "We have all hands on deck.''

He urged New Yorkers to stay at home so that more than 2,000 salt spreaders and snow ploughs can treat the roads.

The storm comes a few days before Boston Mayor Thomas Menino ends 20 years in office.

"I guess Mother Nature wanted to give me one more gift," he told reporters.

Media playback is unsupported on your device Media caption Marci Gonzalez, ABC News, said the sea was freezing in Cohasset harbour

He announced a parking ban and ordered schools to close on Friday. "Take precautions and take public transportation and take care on one another," he told the city's residents.

Massachusetts Governor Deval Patrick closed state offices early on Thursday and told staff to stay away on Friday.

He warned residents not to spent too much time outside because of the frigid temperatures.

"Minimise outside activities... These temperatures are very, very dangerous," he said.

To the south, smaller but still significant amounts of snow are expected in New Jersey and eastern Pennsylvania.

People across the north-east have been stocking up on shovels and salt.

In Hartford, Connecticut, householder Hal Guy was shopping for three snow shovels.

"We broke a couple in the last storm," he told the Associated Press (AP) news agency. "We have four kids, so, three shovels, and we still have a little one back home."

Snowy roads have already been blamed for a vehicle crash in Indiana that killed one person and injured more than a dozen after a lorry lost control and hit a bus carrying 50 people.

A worker at a suburban salt storage facility in Philadelphia was killed when a 100 ft tall pile of road salt fell and crushed him, the AP reports.

The storm's path over 24 hours