The airspace above the northern German city of Hanover was closed to air traffic after unidentified drones were spotted in the area, an airport spokesman said on Saturday, reported dpa. The closure on Friday evening lasted from 9:47 pm (2047 GMT) to 12:16 am, necessitating the diversion of seven aircraft to Paderborn, Bremen, Dusseldorf, Frankfurt and other destinations. Two flights also did not land in Hanover due to the security measures and were therefore unable to depart on Saturday. These were connections to Frankfurt and Paris, which had to be cancelled, reports said. No official details about the drone sighting were initially available. According to a news report in the Hannoversche Allgemeine Zeitung, a drone was first spotted near a model aerodrome in the vicinity at an altitude of around 80 metres. An hour later, according to the report, at least two drones approached the actual airport. In November, Hanover Airport was closed for 45 minutes due to a drone sighting. Rogue drone incursions have disrupted services at several German airports in recent months. Suspicions have fallen on Russia but no evidence of this has been provided. Earlier in December, the head of the Federal Criminal Police Office, Holger Münch, said that more than 1,000 suspicious drone flights had been recorded in Germany so far this year. The incidents most frequently involved military facilities and airports, but also other critical infrastructure such as defence companies and port facilities. Asked whether the drone flights could be attributed to Russian actors, Münch said this could not be determined with certainty, citing the difficulty of identifying and questioning drone operators.