Travel chaos and deaths as US hit by 'bomb cyclone'

A state of emergency has been declared across New York, after a fierce winter storm brought heavy snow and freezing temperatures to the eastern United States.

Storm Grayson has impacted millions along the East Coast, with states of emergency also in place in Florida, Georgia, North Carolina and Virginia.

Blizzard warnings are also in place from Virginia to Maine.

The extreme weather phenomenon - known as a "bomb cyclone" - is caused by a massive drop in pressure bringing with it hurricane-force winds.

Seventeen deaths have been blamed on the extreme weather, including two men killed when their pick-up truck overturned in North Carolina and a passenger who was unable to escape a vehicle that crashed through a railroad crossing 20 miles north of Philadelphia.

Hurricane-force winds have led to power cuts in more than 100,000 homes and businesses across the north east of America.

Impromptu shelters and "warming areas" have been set up in many areas for those experiencing loss of power and burst water pipes.

The North Carolina Highway Patrol responded to 700 collisions and 300 other calls for service during the storm.

All flights had to be suspended from JFK Airport and LaGuardia Airport in New York, and the majority of flights were also severely affected at Newark Airport in New Jersey and Boston airport in Massachusetts.

Flights from JFK were expected to resume on Friday, however. LaGuardia resumed flights late on Thursday.

Many schools were also closed and the Senate cut short its working week due to the extreme weather.

The storm even saw Florida experience its first snowfall in nearly three decades.

Unusually low temperatures in the state caused cold-stunned green iguanas to fall from the trees on to the ground.

Wildlife experts warned residents not to "assume that they are dead", and to be careful not to "threaten" the creatures which they said "may bite once they warm up".

Temperatures were so low in northern New York that Niagara Falls, the waterfalls straddling the US-Canadian border, froze.

Storm Grayson began over Christmas, when an Arctic air mass moved south across America's Great Lakes, colliding with warmer air over the Atlantic Ocean where it picked up power.

The storm will become even more ferocious as it roars up the East Coast, heading towards Canada.