The local defence drills got underway from Monday in the capital region with the strength of about 1,000 troops, half of them reservists.
The focus of the exercises is to put the skills of police and military crews to the test. Troops will also practice official cooperation with the Helsinki police department.
The drills will include simulator-aided combat in Santahamina as well as combat exercises in Hätilä, Hämeenlinna.
The Finnish Defence Forces have warned that the blank ammunition used in the exercises is likely to create alarming noises between the hours 7.00 am and 10.00 pm in areas such as Laajasalo, Karhusaari, Malmi, Vanhakaupunki and Vuosaari.
The series of local defence drills will see three different sets of war games play out across the country, involving a total of roughly 2,100 participants.