BRUSSELS

Swedish police have opened an investigation after residents reported suspicious drones over the Karlskrona archipelago in the country’s east, local media said Friday.

Officers were sent late Thursday to the Mocklosundsbron area after several people on Sturko and Tjurko islands reported sightings, public broadcaster SVT reported. Police at the scene also confirmed seeing one of the unmanned aerial vehicles.

“It is a larger variant, similar to the one that was over Denmark and Skane,” said Mattias Lundgren, the on-duty investigation leader.

Authorities filed reports of violations under both the Aviation Act and the Protection Act, SVT said.

Witnesses told police they saw two drones with red and green flashing lights, according to Evelina Olsson from the regional police command center. No objects were seized and no suspects have been identified.

Lundgren said the drone resembled models recently detected in Denmark and Norway, including those spotted over Copenhagen Airport.

The Swedish Armed Forces were not involved in Thursday’s response. “That would be if something comes to light, but at the moment it is our business,” Olsson said.

The sightings come after Danish authorities temporarily closed airspace over several airports late Thursday following reports of drones, forcing flight diversions. Danish Prime Minister Mette Frederiksen described the incidents as part of “a hybrid war unfolding on Danish soil.”

Copenhagen Airport was shut briefly Tuesday after a drone incursion, diverting at least 31 flights, Danish police said, adding they do not yet know who controls the unmanned aerial vehicles.

A similar disruption occurred late Wednesday at Aalborg Airport in Denmark, which had temporarily shut down and rerouted three flights to other airports due to unidentified drones.

In Norway, the Oslo airport also closed its airspace for three hours Monday after a drone was seen nearby.