WASHINGTON — A small drone has been found on White House grounds, two sources tell CBS News. A spokesman for President Obama told reporters Monday only that a “device” had been found. White House Press Secretary Josh Earnest said early indications were that the device posed no threat to anyone in the building. The Secret Service was investigating, he said. The agency had no immediate comment on what it found. Mr. Obama and his wife, Michelle, are on a three-day visit to India, with a stop planned in Saudi Arabia on Tuesday before they return to Washington. Earnest was responding to a question about a report that a small drone had been found. The White House was dark during Monday’s pre-dawn hours and emergency vehicles with lights flashing were clustered near the southeast entrance to the mansion. A security perimeter had been set up around the White House to restrict access.