Munich Airport said early on Friday that drone sightings on Thursday evening had forced air traffic control to halt operations. An airport spokesperson later said operations resumed as of 5 a.m. local time (0300 UTC/GMT).

"Passengers who were affected by the closure yesterday have been booked on new flights and flights cancelled yesterday will be rescheduled for today," a spokesperson told the AFP news agency.

A Lufthansa spokesperson said, "Flight operations have since resumed according to schedule."

What was the disruption at Munich airport?

The drone sighting prompted the cancellation of more than 30 flights, disrupting travel for nearly 3,000 passengers at the airport in the southern German state of Bavaria.

German police said the airport's runways were closed late in the evening as a precaution. 

Police officers searched the area for suspicious individuals but found nothing. A police helicopter was also deployed.

German interior minister says drone sightings a 'wake-up call'

German Interior Minister Alexander Dobrindt told the mass-market daily Bild that the drone incident in Munich was a "wake-up call."

"The drone sightings over Munich are another wake-up call: The race between drone threats and drone defense is becoming increasingly fierce," Dobrindt told the country's largest circulation publication.

"We now need more funding, support, and research — nationally and at the European level," he added.

Dobrindt said a meeting of European Union interior ministers on Saturday would also address anti-drone defenses.

"At the meeting of European interior ministers this weekend in Munich, we will, in addition to the migration issues, also

explicitly address the situation of drones and the threat posed by drones," he told reporters.

Bavarian Premier Markus Söder called for allowing his state's police force to quickly shoot down drones, a step some experts warned against as it could lead to dangerous debris in civilian areas. 

German authorities have launched a search to identify the origin of the drone or drones.

Recent airport closures in Denmark and Norway

The development comes after sightings temporarily shut airports in Denmark and Norway last week.

The incident comes as Germany's Oktoberfest, which draws hundreds of thousands of people every day to Munich, is approaching its final weekend.

It remains unclear who is behind the drone flights, but there is speculation that Russia may be involved. Moscow has rejected the allegations.

Edited by: Srinivas Mazumdaru