Russia is grounding its Tu-95 long-range bombers pending an investigation of an accident when one of them ran off the runway and an engine caught fire while taking off.

The Tu-95, also known in NATO terminology as "the Bear," is a venerable element of Russia's air power, conducting long-range patrols since the 1950s. It is powered by four turboprop engines.

State news agencies cited the Defense Ministry as saying one of the planes went off the runway when taking off at an airfield in the far-eastern Amur region on Monday. Five crewmen were injured, the independent Interfax news agency reported, citing regional medical officials.

The Tu-95 is capable of carrying nuclear bombs and cruise missiles, but the one in the accident wasn't carrying armaments, the reports said.