Super-storm Sandy has made landfall in the US east coast state of New Jersey causing severe flooding across the eastern seaboard.

Heavy rains and high winds lashed the region forcing the subways and other transportation means to remain closed. In New York, Baltimore, Washington DC, Philadelphia, and Boston public transportation stayed suspended.

Lower Manhattan has been one of the badly affected areas. Nearly 250,000 people were left without power and the region has been plunged in to darkness. Underground electrical systems are also under serious threat of surging sea water.

Up to three million people were left without power supply while another one million people were told to evacuate their homes.

Water levels up to 13 feet, a record high for the area, are reported in the southern tip of Manhattan. Flooding has also been reported in other parts of Manhattan. East Village, Soho, and Battery Park are under flood waters.

"Lower Manhattan is being covered by seawater. I am not exaggerating. Seawater is rushing into the Battery Tunnel," said Howard Glaser, director of operations for the New York state government.

Oyster Creek, the oldest nuclear facility in America located at New Jersey has been put on high alert due to the rising sea water.

New York Mayor Michael Bloomberg said the flood waters would recede in the next hours however, cautioned the people to stay inside their homes. It is estimated that nearly 50 million people who were on the path of Sandy could be affected.

Thousands of flights have been cancelled as all the airports in the New York remain closed. The US stock markets have been closed for both floor and electronic trading.

The Miami-based National Hurricane Center said Sandy made its landfall as a post-tropical cyclone with battering winds of up to 80 mph (129 kph).

It had lost the hurricane status hours before Sandy came ashore, although the winds were higher than that of a hurricane.

Though the exact damage caused by Sandy is yet to be determined, reports suggest it could be anywhere from $ 10bn (£6.2bn) to $20bn (£12.4bn).

Sandy has already forced the US Presidential hopefuls Barack Obama and Mitt Romney to reschedule their campaigns in the crucial week ahead of the elections.

Thirteen people have died in the US due to the hurricane, reported the Associated Press. The hurricane has already killed at least 66 people in Caribbean before reaching the US states.