Tornado touches down near Oklahoma City, emergency declared

A large storm cell, which reportedly produced a multiple vortex tornado, passes south of El Reno, Oklahoma May 31, 2013. REUTERS/Bill Waugh

LITTLE ROCK, Arkansas (Reuters) - A "large and extremely dangerous" tornado that touched down west of Oklahoma City on Friday, causing some damage, was headed toward the city, and a tornado emergency has been declared in the area, the National Weather Service said.

Weather Service meteorologists and storm spotters were tracking the tornado just west of Yukon, a suburb of Oklahoma City, the agency said in a statement. They said it touched down on Interstate 40 and was headed toward Oklahoma City.