UK jets sent to intercept Russian aircraft near British airspace

Further details about the incident weren't immediately available. It is one of the latest incidents in what NATO has said is an increase in Russian military flights near alliance members' territory.

In November, NATO said its members' jets had been scrambled more than 400 times in 2014 to intercept Russian military flights close to members' territories -- a 50% increase over the previous year. The increase harks back to the days of the Cold War, NATO Secretary General Jens Stoltenberg said November 20 during a visit to NATO member Estonia.

"This pattern is risky and unjustified," Stoltenberg said. "So NATO remains vigilant. We are here. And we are ready to defend all allies against any threat."

In a November report, the European Leadership Network listed more than 40 "close military encounters between Russia and the West" in the eight months from March to October.

Three of those -- including a near collision between a Russian military plane and a Swedish passenger aircraft carrying 132 people -- were classified as "high-risk" incidents that could have led to direct military confrontation between Russia and the West, according to the report, titled "Dangerous Brinksmanship."

Russia's relationship with the West has suffered a huge blow because of Moscow's involvement in the crisis in Ukraine.

UK jets intercepted more than 100 Russian aircraft last year, according to the British Defence Ministry.

(CNN)