An explosion Wednesday at a factory in central Russia that produces ballistic missiles was at least the fifth blast in the past four months at one of the Kremlin’s weapons plants, British officials said Friday.

The factory near Izhevsk, 750 miles east of Moscow, manufactures a range of missiles, including the Iskander, which Russia has regularly fired at Ukraine.

Russian officials claimed the explosion was part of a scheduled test of rocket engines. But Radio Free Europe/Radio Liberty said there were no announcements of such a test on Russia’s Ministry of Emergency Situations website.

“There is a realistic possibility that the explosion is due to negligent handling and storing of highly volatile, combustible and explosive materials,” British military officials said on X in their latest assessment of the war in Ukraine.

Russian weapons factories face mounting pressure to increase their output to support the war. It has probably led to round-the-clock production and staff fatigue. “Increased demands on production will highly likely result in greater numbers of industrial accidents in the future,” U.K. officials said.

British analysts dismissed the likelihood that the explosion came from a Ukrainian drone strike because of the daunting distance.

The most recent explosion at a Russian military factory was on Jan. 15 at a chemical plant in Rostov, British officials said.

• Mike Glenn can be reached at mglenn@washingtontimes.com.