By KATHLEEN ELLIS Associated Press

WASHINGTON — Police in Maryland say a gunman has entered the Discovery Communications headquarters in Silver Spring and has taken at least one person hostage.

Montgomery County Police Cpl. Dan Friz tells WJLA-TV that a gunman is in the building.

A person inside the building tells the Associated Press the man had something strapped to his chest and has hostages. The person asked not to be identified, saying people inside have been told not to speak to the media.

Discovery Communications LLC operates cable and satellite networks in the U.S. including The Discovery Channel, TLC and Animal Planet.