The seizures came as Finland debates restrictions on Russian visas following Moscow's February 24 invasion of Ukraine that led to swingeing Western sanctions.

More than 2,500 checks were carried out between July 22 and 27 and around 100 such cases emerged, the customs service said.

"Currently, approximately 20 cases related to passenger traffic are under preliminary examination," a statement said, adding that searches revealed various EU-sanctioned luxury products as well as goods that could have military applications, "such as tools used in maritime traffic."

"There have also been drones as well as such items that we cannot comment on at this moment," Enforcement Director Mikko Gronberg told AFP.

The increasing number of Russian tourists in Finland has spurred discontent as many think tourism should be restricted due to the war in Ukraine.

Finland's conservative opposition party last week proposed a halt to new tourist visas for Russians.

President Sauli Niinisto is due to discuss the issue with the government on Thursday and the proposal appears to have wide backing in parliament.

"Personally, I think restrictions should be increased," Aki Linden from the ruling Social Democrats, who is acting prime minister while Sanna Marin is on holiday, told AFP.

Last week, Kremlin spokesman Dmitry Peskov said Russia "would react very negatively" if there was a curb on Russian visas.

After Russia lifted Covid travel restrictions on July 15, the number of Russian tourists heading to Finland has steadily increased.

Although the numbers are still below pre-Covid levels, there have been more than 185,000 border crossings in July -- up from the 125,000 in June.