As far as the Finnish F-18 Hornet engines are concerned, no actual damage has been proven yet - only particle concentrations spotted. The engine(s) have been dismantled and sent to Patria Aerospace who are examining them at the moment. Results can not be expected until a couple of days later. Finnish Air Force press release in English here:
Puolustusvoimat - Frsvarsmakten - The Finnish Defence Forces
Notice the careful wordings: "may cause" significant damage, etc.