New York governor Andrew Cuomo has declared a state of emergency and authorities are considering an early evacuation, as Hurricane Sandy continues to head towards the east coast of the United States. Sandy, which threatens to be one of the worst storms to hit the area in decades, is expected to make landfall on Monday night or Tuesday in Maryland, Delaware, New Jersey, New York or southern New England.

New York officials are also considering a total shutdown of mass transit systems such as buses and subways before the storm strikes.

"We're expecting a large, large storm. The circulation of this storm as it approaches the coast could cover about the eastern third of the United States," Louis Uccellini, director of the National Oceanic and Atmospheric Administration's Centers for Environmental Prediction told Reuters.

New York mayor Michael Bloomberg is expected to make a decision on evacuations during the weekend.

"We are taking all the steps that we need to take," Bloomberg told reporters on Friday 26 October.

"But the storm is moving at a rate that we're still not going to have a good sense of when and where it's going to hit land. There are probably 20 different forecast tracts for this storm, and any one of them could be right."

The Metropolitan Transportation Authority (MTA) said it will start to shut down buses and subways if the storm reaches 39 mph.

"Our first priority is always safety, and the MTA is taking no chances with the safety of our customers, our employees and our equipment," said MTA Chairman Joseph Lhota. If MTA does halt services, it would be for the second time in the history of the organisation, the first being at the time of Hurricane Irene in 2011.

Sandy has already been dubbed "Frankenstorm' by some weather forecasters as it is expected to combine the characteristics of a tropical cyclone and a winter storm. It has slowed down to a Category 1 hurricane from the previous strength of Category 2 when it hit Cuba.

At 7am BST, the hurricane was heading north over the Bahamas with a maximum wind speed of 70mph (110km/h) and was 600km south-east of Charleston in South Carolina, according to the National Hurricane Centre.

Sandy has already caused devastation in the Caribbean, killing at least 41 people in the region.

At least 11 people have been killed in Cuba and nearly 5,000 homes are partially collapsed with another 30,000 left without roofs. Up to 26 people have been killed in impoverished Haiti and four people deaths have been reported in the Dominican Republic, Jamaica and the Bahamas.

In the Bahamas archipelago, the storm toppled electricity poles, flooded streets and knocked down tree branches.

These pictures show the magnitude of the devastation caused by Hurricane Sandy in the Caribbean.