Defence Minister Antti Häkkänen (NCP) signed a total of six negative permit decisions regarding real estate transactions by purchasers from outside the EU and European Economic Area (EEA), according to a defence ministry press release on Friday.
The ministry said the decisions were based on grounds of national security and the Act on Transfers of Real Estate Requiring Special Permission.
All of the properties are located in eastern areas of Finland.
"The Ministry of Defence justifies the decisions by stating, among other things, that it cannot be ruled out that the real estate acquisitions in question could threaten national security and hinder the organisation of national defence or the surveillance and safeguarding of territorial integrity," the ministry said in the release.
The properties in question are located in Imatra and Kouvola, in southeastern Finland, as well as in the city of Mikkeli, in South Savo. The three other properties are in the North Karelian municipality of Lieksa, the ministry said.
The ministry said the prospective buyers of properties in Mikkeli, Lieksa and Imatra were private individuals, "while the transaction in Kouvola was made by a company".
"Both the private individuals and actual beneficiaries of the company are Russian, Ukrainian and Swiss citizens," the ministry said.
It said authorities are also able to stop such property purchases due to unpaid permit fees "or because the intended use of the real estate is not credible".