"A drone was jammed yesterday by a Swedish system at about seven nautical miles from the Charles de Gaulle. The Swedish system worked perfectly and this did not disrupt operations on board," French General Staff spokesman Colonel Guillaume Vernet told AFP.

The incident took place in the Oresund Strait, near the city of Malmo where the French flagship made a stopover on Wednesday, the Swedish army said in a statement.

"A vessel from the Swedish Navy observed a suspected drone during an ongoing maritime patrol" and "the Swedish Armed Forces took countermeasures to disrupt the suspected drone" before losing contact, the statement said.

It added that there had been "no further drone sightings" and an investigation was underway.

The carrier strike group, led by the French Navy's flagship and its escort, made a port call on Wednesday for the first time in Malmo, Sweden, before joining NATO exercises.

The nearby Baltic Sea is a theatre of rivalry between Russia and the countries of the North Atlantic alliance.

"The carrier strike group is equipped with its own protection systems, but when it enters the sovereign waters of a partner, as is the case here, it comes under the protection of the host country," Vernet said.

Jamming a drone uses electronic warfare to attempt to break the connection between the aircraft and its operator or disrupt its navigation tools.

The incident was the latest in a series of mysterious drone flights over airports and sensitive military and industrial sites across Europe.

In December, the French military used jammers as several suspected drones flew over a closely guarded base housing nuclear ballistic submarines.

French authorities launched an investigation into the drones' origins.

Four years into Russia's invasion of Ukraine, there is growing concern that such disruption could be part of hybrid war tactics by Moscow against the European Union, which has backed Kyiv.