Russian fighter jets accompanied Tu-95 Bear bombers that flew near Alaska Thursday in the most recent example of the Kremlin's stepped-up military activity in the area, NORAD said.

The two Su-35 Flanker jets and the nuclear-capable bombers remained in international airspace and were intercepted around 5 p.m. by two U.S. F-22 fighters that are stationed in Alaska, according to the command.

Russian bomber activity has increased off the Alaska coast recently, with four incidents in a single week last month, but the fighter jet escort is more rare and has not been seen for several years, said Lori O'Donley, a spokeswoman for the North American Aerospace Defense Command.

"The last time we saw fighters with bombers together was 2014," O'Donley wrote in an email.

The United States has intercepted Russian aircraft about 60 times since 2007. Some years have seen up to 15 incidents while other years have none, according to the command.

Three of the incidents in April involved long-range Russian bombers and the scrambling of U.S. stealth jets, and a fourth involved the sighting of a Russian Il-38 maritime patrol aircraft.

The Russian fly-bys come amid tensions with the new Trump administration over Moscow's support of Bashar Assad's regime in Syria, aggression toward Europe and meddling in the U.S. presidential election.