WASHINGTON (Reuters) - Churches canceled services on Sunday and millions of people dug themselves out of snowbound streets as the mid-Atlantic region struggled to recover from its biggest blizzard in decades.

More than 100,000 households were without power and two of the region's three main airports remained closed after more than 30 hours of snowfall dumped two feet (half a meter) of snow across a region not used to big snowstorms.

Weather forecasters said another was due to hit the area on Tuesday and warned of bitter cold temperatures following the "Blizzard of 2010." ABC news said Tuesday's storm could bring another 12 inches of snow.

Many schools announced that classes were canceled through Tuesday and authorities warned people to stay off roads that remained snow-covered and barely passable. Bus service was suspended in the U.S. capital and subway trains ran only within the underground section of the network.

Snowfall totals of 20 to 38 inches blanketed a wide arch from West Virginia to southern New Jersey by early Saturday evening when the flakes stopped falling after more than 24 hours.

More than 100,000 homes lost power in the Washington area, according to local television, after the snow felled trees, and brought down power lines. The Pepco electric company said 64,000 customers were without power, and the Dominion power company reported another 29,000 households without service.

Winter sunshine bathed the nation's capital, where pedestrians outnumbered cars on deserted and mostly unplowed streets. Up to 32 inches of snow had fallen in suburban Washington in the biggest snowfall to hit the city in decades.

Two of the Washington-Baltimore area's three main airports remained largely closed. Baltimore-Washington International airport said it expected "limited, if any, commercial flight activity" on Sunday and most flights were listed as canceled.

Dulles Airport outside Washington was open for a limited number of flights, but it was uncertain how many would operate, the airport's web site said.

On Friday, the storm brought school closings and long lines at supermarkets, as residents rushed to stock up on groceries and other supplies ahead of the Super Bowl on Sunday, when tens of millions are expected to gather in homes and bars to watch the football championship.

Virginia, Maryland and the District of Columbia declared snow emergencies, allowing them to activate emergency agencies, including the National Guard, to help deal with the storm. (Reporting by Paul Eckert; Editing by Paul Simao)