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.

People walk on a street littered with debris after Hurricane Sandy hit Santiago de Cuba.Reuters
A cook walks amidst the debris at a hotel after Hurricane Sandy hit Santiago de Cuba.Reuters
A man salvages planks from his damaged house after Hurricane Sandy hit Santiago de Cuba.Reuters
Coconut tree falls and is washed away by rains from Hurricane Sandy, as river swells to dangerous levels, in Port-au-Prince.Reuters
A Haitian woman scoops mud from Hurricane Sandy out of her flooded tent home in Port-au-Prince.Reuters
Hurricane Sandy is pictured making landfall over Cuba in this NASA handout infrared satellite image.Reuters
Residents of Kingston try to cross the Hope River after a bridge was washed out by Hurricane Sandy.Reuters
A resident salvages a refrigerator from his damaged house, with the help of other men, after Hurricane Sandy hit Santiago de Cuba.Reuters
Workers repair a utility pole damaged by Hurricane Sandy in Kingston.Reuters
NASA handout image of Hurricane Sandy.Reuters
Jean Marie Brennan walks along the jetty at Lighthouse Point Park as Hurricane Sandy passes offshore in Ponce Inlet.Reuters
A woman looks at a fallen tree on top of her house after Hurricane Sandy hit Santiago de Cuba.Reuters
A surfer takes advantage of higher waves as winds from Hurricane Sandy began to affect weather in Boca Raton.Reuters
A red flag flies after lifeguards closed the area for swimming because of dangerous rip currents, as winds from Hurricane Sandy began to affect weather in Deerfield Beach.Reuters
A view of the Hope River as it begins to swell with rain from approaching Hurricane Sandy in Kingston.Reuters
New York Mayor Bloomberg speaks to the media during a news conference on preparations for Hurricane Sandy in New York.Reuters