Following multiple incursions, European leaders are seeking to build an anti-drone "wall" for protection.

Switzerland is not part of the European Union or the NATO defence alliance, but is also seeking to protect itself from potential attacks after a series of drone sightings over military zones in the country, officials said.

It is "essential to take effective measures against enemy mini-drones", the military said in a statement.

"The next step is to choose the model in order to introduce the system in the near future."

Army spokeswoman Delphine Schwab-Allemand told AFP: "The army currently has no means of protection and defence against microdrones, mini-drones, and small drones."

She said the Swiss army had "repeatedly spotted mini-drones" this year "over military grounds or near military exercises outside of training areas".

"We have seen an increase in these types of incidents since last year," she added, while indicating that the army, for operational reasons, does not reveal the number of such incidents, their nature or the procedure for tracking down the pilots.

Switzerland's long-standing position has been one of well-armed military neutrality, and the landlocked European country has mandatory conscription for men.

In recent months, the military field-tested a defence system that could detect and intercept mini-drones posing a threat to military infrastructure.

"The positive conclusions of this test, combined with the proliferation of drones", spurred the armed forces into seeking "to acquire this system as a matter of priority and thus strengthen the protection of the army's troops, infrastructure and equipment", the military said.

EU countries suspect Russia of being behind drone overflights of sensitive sites, which have increased in recent days.

Besides seeking an anti-drone system, Switzerland's Federal Office for Defence Procurement has struck framework contracts with three suppliers to buy commercially available mini-drones.