Traffic was suspended at Gothenburg Airport on Sweden's west coast on Thursday after multiple drones were spotted, authorities said, Reuters reports.
Drones have caused widespread disruption and disruption across Europe in recent months, forcing the temporary closure of airports in several countries. Some officials have attributed the incidents to Russian hybrid warfare, but Moscow has denied any connection.
"One or more drones have been spotted at Landvetter Airport," a spokesman for the Swedish Civil Aviation Authority (LFV) said.
A police spokesman said police received a report of suspicious aircraft from multiple individuals at 16:41 GMT and that police teams were on the scene, gathering information and trying to confirm the reports.
"We have launched an investigation into suspected sabotage in the air force," a police spokesman added.
According to the airport operator, Landvetter is the second largest airport in Sweden, right after Stockholm Arlanda.
"The airspace over Landwetter is currently closed due to indications of a possible drone presence," said operations director Susan Norman.
"The airspace will remain closed until the police complete their investigation."
On Tuesday, reported drone sightings prompted the closure of an airport and military base in Belgium, in what the country's defense minister described as a coordinated attack, according to Reuters.
On Thursday, police authorities in neighboring Norway said they had closed an investigation into suspicious drone flights that led to the closure of Oslo Airport in September, saying there was insufficient evidence that drones were actually present.
In neighboring Denmark, several airports, including Copenhagen, were also temporarily closed in September due to reported drones.
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