Switzerland's armed forces say five aircraft breached the restricted airspace over the Bürgenstock during this weekend's US-Iran talks.
The air force visually identified two of them and escorted them out of the security zone.
The Federal Council had authorised up to 2,000 troops to back civilian forces and enforce the airspace closure, standard at events of this scale.
The defence department says co-operation with civilian agencies went smoothly and the operation added only marginal cost on top of the army's regular budget.
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