U.S. gasoline stockpiles fell sharply over the past week, while inventories of crude oil and other refined fuels increased, the Energy Department reported Wednesday.

In the week ending April 6, the nation's gasoline supplies plunged by 5.5 million barrels to 199.7 million, the department said in its weekly survey of petroleum inventories.

Analysts had been expecting a 1.3 million barrel decline in gasoline inventories.

The sharp fall in gasoline supplies came amid strong demand as summer driving season is coming soon.

Gasoline demand averaged 9.4 million barrels per day over the past four weeks, or 2.5 percent higher than the year-ago period, according to the department.

U.S. commercial crude oil inventories, however, rose by 700,000barrels last week to 333.4 million. But the gain was smaller than the 1.6 million barrels expected by analysts.

Meanwhile, stocks of distillate fuels, which include heating oil and diesel, increased by 100,000 barrels to 118.1 million barrels. That was defying analysts' expectations of a decline of 900,000 barrels.

The figures for commercial crude oil inventories do not include the U.S. Strategic Petroleum Reserve, which currently holds crude oil of about 689 million barrels.