Police in the United Kingdom have released two people—who have not yet been identified—arrested after an incursion of at least one drone into the airspace of Gatwick airport last week.

According to The Verge—a website that reports on developments in technology—flights into and out of England's second largest airport were disrupted when a drone was spotted flying in the area.

The suspects had been held on "suspicion of disrupting services of civil aviation aerodrome to endanger or likely to endanger safety of operations or persons," but were released without charges.

Authorities said the investigation remains ongoing.