Two U.S. F-35 fighter jets intercepted Russian fighter aircraft Tuesday as they approached Alaska’s Air Defense Identification Zone, officials announced Thursday.

The Russian military aircraft included a TU-95 BEAR-H bomber, as well as SU-30 and SU-35 fighter jets.

North American Aerospace Defense Command (NORAD), which detected and intercepted the craft, said that it did not enter U.S. airspace.

NORAD stated that the incident was not related to the spate of unidentified aircraft seen in recent weeks, calling the situation “routine.”

Two F-16 fighter jets were previously dispatched by NORAD to intercept separate Russian aircraft on Monday, which included a TU-95 BEARH-H and SU-35 fighter jet.

“This is the second intercept of Russian aircraft over two days. This Russian activity near the North American ADIZ occurs regularly and is not seen as a threat, nor is the activity seen as provocative,” NORAD said Thursday.