WASHINGTON—Cautioning citizens to be on high alert and remain indoors until the area was determined to be safe, authorities confirmed Thursday that the United States is still an active shooter situation. “The violent situation in this nation is still developing, so it is absolutely essential that the American population lock their doors and stay away from windows until all threats have been neutralized,” said FBI director James Comey, who urged those within the country’s borders to turn off all lights and take cover while the shooting rampage taking place across the nation is still underway. “Right now, this 3.8-million-square-mile area is still very dangerous. We are working to ascertain how many suspects there are and secure the location, but at this point, we can’t say exactly when that might be. We will continue to update American citizens regularly as we learn more.” Comey added that individuals who live or work within the country should check in with their loved ones to let them know they’re safe.