Germany's Munich airport closed and cancelled more than a dozen flights on Thursday night after drones were seen close to its airspace.

At least 17 flights were grounded in Munich, affecting nearly 3,000 passengers.

Munich Airport said it diverted a further 15 flights to nearby cities.

There was no immediate confirmation of where the drones had come from. Several airports across Europe have closed down in recent weeks because of unidentified drones.

Munich airport alerted authorities after the drones were detected. Flights out of Munich airport were "suspended", the airport said, and the airport closed two hours ahead of its usual midnight to 05:00 curfew.

Air traffic control redirected flights that were due to land in Munich to Stuttgart, Nuremberg, Vienna, and Frankfurt.

Because it was dark, no information on the type, size or origins of the drones was confirmed, Federal Police spokesperson Stefan Bayer told the Bild Newspaper. The drones were first seen at 21:30 local time (19:30 GMT), and then again an hour later, police said.

The BBC has contacted Germany's federal police.

Recent drone sightings across the European Union prompted a leaders' summit in Copenhagen this week.

20 Russian drones crossed into Poland and Russian MiG-31 jets entered Estonian airspace in separate recent incidents.

Copenhagen and Oslo airports were forced to close after unidentified drones were spotted near airport and military airspaces.

Russia has denied any involvement, while Danish authorities say there was no evidence Moscow was involved.

Speaking to a summit in the Black Sea resort city of Sochi on Thursday, Russian President Vladimir Putin laughed off suggestions he ordered drones to Denmark.

"I won't do it again. I won't do it again - not to France or Denmark or Copenhagen", Putin said.

Thousands of passengers were stranded at Munich airport overnight.

"Camp beds were set up, and blankets, drinks, and snacks were provided," the airport said.

The city is currently hosting the annual Oktoberfest festival, which is due to end on 5 October. The festival attracts more than six million people a year, according to the official website.