Washington, Aug 28 (IANS/RIA Novosti): Four people, including a child, were killed Saturday as a result of powerful hurricane Irene that has hit the US East Coast, emergency officials said.

Three people died in North Carolina. One of them was killed by a falling tree, another one suffered a heat attack, and a third one was killed in a road accident after loosing control of his car on a road flooded by heavy rain.

In Virginia, an 11-year-old boy was killed when the hurricane blew a tree onto a two-story apartment building.

Some media reports put the death toll at five.

A state of emergency has been declared in nine US states as Irene, described by President Barack Obama as a "historic hurricane", made a landfall on the eastern coast early Saturday, packing winds of more than 140km/h. The storm was downgraded to category 1 from category 2 on the Saffir-Simpson scale after it came ashore.

More than two million people have been ordered to evacuate Saturday from areas that were expected to be flooded by downpours brought by the storm. The country's largest subway system in New York and flights at the five main New York airports have been halted Saturday afternoon over the storm.

The hurricane has cut off power supply to nearly one million residents in the states of Virginia, North Carolina, Maryland and the district of Columbia.

The storm has moved steadily to the north, making heavily populated areas of Washington, D.C., and New York city to brace for impact. It is now approaching the city of Norfolk, Virginia, which hosts one of the largest US military bases.

The hurricane was expected to continue moving northward through New England before weakening early Sunday.