Finland's Defense Ministry says it suspects a Russian warplane has violated Finnish airspace, forcing Finland to scramble military jets to identify the Su-27 fighter flying over the Baltic Sea.
The ministry said in a statement that the "suspected violation" on October 6 continued for about one minute and the plane traveled about 13 kilometers -- going as far into Finnish airspace as 1 kilometer.
Russia's Defense Ministry denied that the Su-27 strayed into Finnish airspace, saying it was on "a scheduled training mission over the neutral waters of the Gulf of Finland."
"The aircraft of the Russian Aerospace Force has been performing all flights in strict compliance with international regulations," the ministry said.
Finland has accused Russia of several breaches of its airspace since Russia seized Ukraine's Crimean Peninsula and illegally annexed the region in 2014.
In April 2016, two Russian warplanes flew simulated attack passes near a U.S. guided-missile destroyer in the Baltic Sea.
Finland says its national border guard is investigating the latest incident.