Frankfurt airport is operating again after several drone sightings prompted the suspension of all flights for almost two hours.

German air navigation service provider DFS suspended all incoming and outgoing flights between about 11.20 a.m. and 1 p.m. after a pilot spotted a drone, Fraport AG spokesman Dieter Hulick said by phone. Airlines canceled 77 flights so far, of which 64 flights were diverted to other airports. On Monday, a total of 1,300 services had been scheduled at Frankfurt airport.

A spokesman for the federal police said after the initial report, three or four more drone sightings took place and the police searched with a helicopter.