— -- NATO intercepted at least 19 Russian aircraft flying far outside Russia's airspace today, worrying the organization's officials.
"These sizable Russian flights represent an unusual level of air activity over European airspace," NATO said in a statement released this afternoon.
The Russian fighter jets and bombers were seen flying in three different regions. The intercepts came a week after widespread reports that a Russian submarine may have been spotted off the coast of Sweden.
The North Sea and Atlantic Ocean had the largest fleet of Russian aircraft activity, with eight planes detected by NATO radar flying in formation from Russian airspace toward the Norwegian Sea and into international airspace this afternoon.
NATO allies, which continually watch over partner airspace, saw six of the planes turn back towards northern Russia after Norwegian Air Force F-16s intercepted the planes. The remaining two Russian planes, both Tu-95 Bear H bombers, continued to fly above the Norwegian coastline, prompting NATO planes stationed in the United Kingdom to track them.
The NATO statement reported that those two Russian bombers were en route back to their homeland.
"Scrambles and intercepts are standard procedure when an unknown aircraft approaches NATO airspace," the NATO release said. "However, such flights pose a potential risk to civil aviation given that the Russian military often do not file flight plans, or use their on-board transponders."
Four other Russian aircraft -- two fighter jets and two bombers -- were spotted flying over the Black Sea, prompting Turkish Air Force jets to scramble to track them.
There were at least seven other Russian planes intercepted over the Baltic Sea today, as well, though NATO would not indicate exactly how many. Baltic Air Policing Mission planes were sent into the air and the Russian aircraft headed back to their own airspace.
Russian officials have not yet reacted to the NATO report.
The nearly 20 intercepts came after seven other Russian jets were intercepted over the Baltic Sea on Tuesday.