According to the Defence Forces, this was a precautionary measure against drones straying into Finnish territory.A Finnish Air Force Hornet fighter jet at an airshow in Tikkakoski last month. Image: Jussi Lindroos / YleYle News10:25The Finnish Defence Forces (FDF) temporarily restricted aviation over the eastern Gulf of Finland early on Thursday morning.The temporary airspace restriction was imposed around 4:30am and lifted shortly after 6am."The Defence Forces have introduced a temporary aviation restriction area in the eastern Gulf of Finland on Thursday 2 July at 4.26. Always check airspace restrictions before taking off – this applies to both manned and unmanned aviation," the FDF said in a social media post.According to the FDF, this was a precautionary measure due to the possibility of drones straying into Finnish territory. However, no drones were detected, so the restriction was lifted.Meanwhile the Russian Defence Ministry says it shot down 327 Ukrainian drones overnight, Reuters reports. Russia also carried out heavy strikes on Ukraine overnight, killing at least eight people in the capital Kyiv.The FDF most recently announced a similar airspace closure on 6 June, when it restricted aviation over maritime areas near Kotka and Hamina on the southeastern coast.At the time, it said the measure was related to Ukraine's defence against Russia, but further details were not made public.Before that, a general drone alert was issued in the Uusimaa region on 15 May, following the discovery of several drones in southeast Finland in March.