The French and Swedish militaries will help fortify Copenhagen against aerial threats as European leaders converge on the city for two crunch summits this week.

Swedish Prime Minister Ulf Kristersson announced Monday his government had deployed “the Swedish Armed Forces to support Denmark with military anti-drone capabilities in connection with this week’s summits in Copenhagen,” including a specialized unit that will embed with the Danish military.

Stockholm would also “lend a handful of powerful radar systems to Denmark for a period of time,” he added.

Denmark was rattled by a wave of drone sightings at major airports and military air bases last week, disrupting air traffic and stranding thousands of passengers. Prime Minister Mette Frederiksen said the airspace breaches amounted to “hybrid war” and hinted Russia was responsible.

The incidents, which occurred ahead of Wednesday’s European Council meeting in Copenhagen to discuss defense and Ukraine, led the Danish authorities to take the dramatic step of closing the country’s airspace to civilian drones.

France said Monday it had also sent its armed forces to shore up Copenhagen’s defenses.

Paris deployed “35 personnel, a FENNEC helicopter, and active counter-drone assets” to Denmark “in response to the recent upsurge in unidentified drone flights in Danish airspace,” the French defense ministry said in a statement, adding the drones were a “serious threat.”

In addition, a German frigate — the FSG Hamburg — arrived in Copenhagen over the weekend to assist with airspace surveillance.

Along with Wednesday’s summit, Copenhagen will host the European Political Community on Thursday, bringing together leaders from across the continent.