A Russian frigate fired two flares toward a Danish military helicopter in international waters on Monday, Danish authorities have said. The helicopter was on a routine mission to photograph the Russian frigate off the coast of Denmark when two warning flares were fired, one of which passed the helicopter at close range, the country’s foreign ministry said in a statement. Danish Foreign Minister Lars Løkke Rasmussen called the incident “completely unacceptable” and summoned Russia’s ambassador in Copenhagen. Jeppe Bruus, Danish Defense Minister, said that the incident is “a sign that the boundaries have been moved when it comes to risk-taking on the Russian side.” Europe has been on high alert in recent weeks amid concerns over potential Russian provocations, including hybrid attacks and possible border violations.