Two Russian bomber planes were spotted east of the big Swedish island of Gotland on Saturday morning. After the coastal sighting, the Swedish Armed Forces sent up two fighter jets to monitor the bombers’ activities, The Local reported.

The Swedish Armed Forces said the planes did not violate Swedish airspace. Other nations sent up planes to monitor the bombers as well, the Swedish Armed Forces said, but declined to disclose which nations those were.

“It is our task to keep track of what is happening in our neighborhood. It is not a serious event but something that happens quite often," said Marie Tisäter, duty officer at the Swedish Armed Forces, according to The Local. “We often help with other countries' operations in the Baltic Sea and they also help us.”

Sweden and Russia have experienced increasingly high tensions in the past year. In September 2014, when two bombers allegedly entered the Swedish airspace, former Foreign Minister Carl Bildt called it "the most serious aerial incursion by the Russians" in almost a decade, The Local reported.  Russia hadreportedly also illegally gathered information on Swedish defense, politics and technology in 2014, heightening tensions between the two countries. Claims were also made in March that 33,000 Russian soldiers practiced a simulated military takeover of Gotland, Sweden's largest island and a favorite holiday destination for Swedes. It lies off the southeastern coast of Sweden in the Baltic Sea. 

As a result of such activity, Defense Minister Peter Hultqvist said in June that Sweden would be stepping up its military capabilities and exercises with NATO, Agence France-Presse reported. Sweden also has plans to station 230 troops on Gotland from 2018, which would make Gotland Sweden’s first line of defense to the east, according to The Local.

"It's a general fact that Russia is carrying out bigger, more complex, and in some cases more provocative and defiant, exercises,” Hultqvist told Dagens Nyheter, Agence France-Presse reported. “We are following that development and are now strengthening our military capability and our international cooperation.”