"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.
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."
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.