June 7 (UPI) — The smell of smoke prompted the evacuation of the control tower at Munich Airport for nearly two hours on Sunday, forcing all flight operations to be suspended.

The smell of burning was detected in the control tower around 8:50 p.m. local time, German broadcaster BR reported.

Although no flames were seen, the fire department was called in and the tower was evacuated, forcing all takeoffs and landings at the busy airport to be suspended.

Aircraft originally scheduled to land in Munich were diverted to alternative airports, an airport spokesperson said.

After fire officials assessed the situation, flight operations were allowed to resume at 10:15 p.m., airport officials said in an update.

What caused the burning smell remained unclear after the initial probe.

German Federal Police told the DPA news agency investigators “don’t know for sure yet” where the burning smell came from, and later clarified to the Munich newspaper Suddeutsche Zeitung that there was no fire in the tower.

The cause of episode remained under investigation late on Sunday.

Munich Airport ranks eighth among the largest airports in Europe in terms of flight movements with 43.4 million total passengers passing through its gates in 2025, according to the Munich Airport Statistical Yearbook.

Some 91 airlines offered regular services at Munich Airport last year, totaling 232 destinations in 72 countries, including 14 destinations in Germany, as well as 162 medium-haul and 56 long-haul destinations.

That gave Munich Airport one of the densest route networks in Europe.