The intermediate-range ballistic missile that Russia shot at a Ukrainian munitions factory in Dnipro last week was “almost certainly” developed before Moscow announced its withdrawal from 2019’s Intermediate Nuclear Forces Treaty that banned IRBMs, British officials said Friday.

The Nov. 21 strike was the first use of the Russian IRBM, code-named Oreshnik. It carried a payload of six warheads containing a total of 36 submunitions, U.K. military intelligence officials said on X in their latest assessment of the Ukraine battlefield.

“These submunitions travel at hypersonic speeds — greater than Mach 5 — before impact, as is typical for a missile of this class,” the officials said. “All IRBM and intercontinental ballistic missile warheads will travel at hypersonic speeds when reentering the atmosphere.”

The Oreshnik is likely a variant of the RS-26 Rubezh ballistic missile first tested in 2011. The use of what British analysts called an experimental system against Ukraine was almost certainly intended as strategic messaging following the use by Ukraine of Western missiles into Russia.

“Russia highly likely only has a handful of Oreshnik missiles, which are yet to enter serial production,” British officials said. “The missile is highly likely to be far more expensive than other missiles Russia is currently using against Ukraine.”

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