Polish Prime Minister Donald Tusk said in a televised interview on May 20 that his country's authorities had arrested nine people suspected of saboteur activities under the supervision of Russian secret services. According to Tusk, the suspects, who are citizens of Belarus, Ukraine, and Poland, planned acts of sabotage in Poland and Lithuania. Tusk called the situation "very serious," adding that similar saboteur actions were planned by Russian secret services in Latvia and Sweden. Polish President Andrzej Duda said earlier that several recent serious fires in the country may have been caused by arson attacks. To read the original story by RFE/RL's Russian Service, click here.