A plane belonging to the Department of Homeland Security flew for hours in the sky over downtown Portland Wednesday night in what may be a surveillance operation, according to the Washington Examiner’s search of flight data.

The small plane, a Beechcraft Super King Air 350, departed from Bellingham International Airport in northwest Washington state and went several hundred miles south to Portland then flew in circles at 10,000 feet over the northwestern side of the city for nearly three hours before landing at Portland International Airport, according to flight records. It took off again an hour later, flying again around downtown then returned to Bellingham shortly before 2 a.m. local time.