A man walks under an umbrella in falling snow as he is reflected in a window of a nearby building in the New York city suburb of Nyack January 28, 2009. A winter storm hit the northeast United States Wednesday with snow, freezing rain and sleet.

WASHINGTON, Jan. 28 (Xinhua) -- A snow storm has been blanketing the midsection of the United States from Oklahoma to Maryland since Monday, claiming at least 21 lives and leaving nearly a million in the dark, authorities said on Wednesday.

The National Weather Service issued several storm warnings and said the storm is moving to the northeastern United States and is expected to bring heavy snow to the states of Ohio, Pennsylvania and New York.

The storm has so far claimed at least six lives in Texas, four in Arkansas, three in Virginia, five in Missouri, two in Oklahoma and one in Indiana, according to statistics from these states.

Of the over 900,000 households left in the dark, more than 400,000 are in Kentucky.

Jay Blanton, spokesman for Kentucky governor Steve Beshear, said the state has set up 45 shelters to help residents battling icy conditions.

More than 300,000 customers in Arkansas lost power, so did 265,000 more in the states of Oklahoma, Illinois, Indiana, Ohio and West Virginia.

Heavy snow fell in many areas from Tuesday to Wednesday.

Parts of Pennsylvania and Maryland were hit by 10 centimeters of snow, parts of Missouri, Illinois and Indiana by 15 cm, and areas of Ohio 30 cm.

Weather-related flight delays were reported at New York's La Guardia and Washington DC's Dulles International airports as well as those in Dallas, Philadelphia and Newark, according to the website of the Federal Aviation Administration.