A drone may have been flying over Uusimaa, but it no longer poses a danger.
People were advised to move indoors and remain there.
Air traffic at Helsinki Airport was temporarily suspended, but has since resumed.
Finnish Air Force Hornet fighter jets were seen flying over Uusimaa and off the coast of Helsinki early on Friday morning.
The Defence Forces said the expected target area of drones that may have strayed into Finland is the region between Helsinki and Porvoo.
Finnish President Alexander Stubb on Friday morning took to X to say Finland was not facing a direct military threat. Posting on the same platform, Interior Minister Mari Rantanen (Finns) said it was safe to go to school and work.
4am warning
The Finnish Defence Forces said it strengthened its surveillance and counter-capability early Friday morning after learning that drones may have strayed into Finland.
The measures included increasing air surveillance personnel, intensifying fighter jet readiness, and stepping up the use of army helicopters and naval vessels. The Border Guard also raised its readiness level.
The Defence Forces imposed a temporary restricted airspace from 04:00 to ensure public safety.
Air traffic at Helsinki Airport and maritime traffic in the Gulf of Finland were rerouted from 4am onward.
Emergency authorities issued a warning for the Uusimaa region at 03:49.
This story is being updated.
