A flash of high winds and severe thunderstorms swept across the Washington region Saturday afternoon, leaving roughly 200,000 residents from Northern Virginia to Baltimore without power and some people in Prince George's County injured.

The National Weather Service reported winds as high as 70 miles per hour were reported in some areas of the Washington region after what had been a mild morning and afternoon. Residents were urged to avoid roads and stay indoors if possible.

Twelve people at the Prince George's County Fair were trampled as fairgoers made their way to the crowded exits of the Showplace Arena in Upper Marlboro. Two or three sustained injuries requiring them to be transported to a local hospital, according to Fire/EMS spokesman Mark Brady.

Elsewhere in Prince George's and Montgomery County, police and fire officials reported high volumes of calls from residents, but few significant incidents.

Fairfax County, one of the first hit by the storm, reported two tornados had touched down in Centreville and Bull Run, according to a county police spokesman. Police reported 23 road closures as of about 5 p.m. Saturday afternoon, and urged drivers to use caution while making their way past downed power lines and through intersections without working traffic signals.

Dominion Power reported more than 90,404 customers in Northern Virginia without power as of 6:40 p.m. Saturday.

Nearly 56,595 Pepco customers in Maryland and the District were without power Saturday afternoon, as were 1,650 BGE customers in Prince George's County. More than 20,424 BGE customers were without power at one point Saturday.

Powerful winds in the District knocked down a traffic sign hanging above the entrance to the 3rd Street Tunnel on the Southeast-Southwest Freeway, blocking some lanes of traffic on the freeway.

D.C. Fire and EMS reported unspecified damage to a building under construction on the 300 block of H Street Northeast, as well as about a dozen road closures due to downed trees, power lines and high water.