Britain’s defense ministry has cast doubt on Russia’s ability to continue to produce weapons during its invasion of Ukraine.

In an intelligence update posted to Twitter on Sunday, the ministry estimated that Russia fired more than 80 cruise missiles into Ukraine on Oct. 10, a move that Russian President Vladimir Putin said was in retaliation for the bombing of the bridge that links Russia to the annexed Crimean Peninsula earlier this month.  There has been no claim of responsibility for the blast.

“Russia’s defense industry is probably incapable of producing advanced munitions at the rate they are being expended,” Britain said. “These attacks represent a further degradation of Russia’s long-range missile stocks, which is likely to constrain their ability to strike the volume of targets they desire in future.”

Meanwhile, Ukrainian President Volodymyr Zelenskyy, in his daily address Saturday, thanked the U.S. for its $725 million assistance package, enabling Ukraine to purchase ammunition, artillery, anti-tanks weapons and anti-radar missiles.

Russian strikes continue

Russian forces carried out more sporadic missile strikes Saturday in Ukraine, targeting facilities that provide power to the country and its residential areas.

Kyiv regional Governor Oleksiy Kuleba said the attack damaged a key energy facility in Ukraine’s capital region, but no causalities were reported, and the location was not disclosed.

Kyrylo Tymoshenko, the deputy head of the Ukrainian president’s office, urged Kyiv-area residents and people in three neighboring regions to conserve energy during the evening hours of peak demand.

The attack on the power transmission facility came hours after Ukrainian officials said Russia fired artillery into residential areas of Nikopol, southeast of Zaporizhzhia. Yevhen Yevtushenko, head of the Nikopol district military administration, said five people were wounded in the Saturday morning attack on the city. He said the attacks were focused on “maximum damage to civilians.”

Russians killed at firing range

At least 11 Russian troops were killed and 15 more were wounded Saturday when two Russian volunteer soldiers opened fire at a military firing range in the southwest Belgorod region near Ukraine, according to the Russian defense ministry.

The defense ministry said the pair of volunteers were from a former Soviet nation and were killed by return fire, describing the incident as a terrorist attack.

“During a firearms training session with individuals who voluntarily expressed a desire to participate in the special military operation (against Ukraine), the terrorists opened fire with small arms on the personnel of the unit,” RIA cited a defense ministry statement as saying.

Some Russian independent media outlets were reporting higher casualties.

Oleksiy Arestovych, an adviser to Ukrainian President Volodymyr Zelenskyy, said in an interview that the attackers were from Tajikistan and had opened fire after an argument over religion, Reuters reported.

Tajikistan is a predominantly Muslim nation in Central Asia. About half of Russians follow various branches of Christianity. The Russian ministry had said the attackers were from a nation in the Commonwealth of Independent States, which includes Tajikistan.

Reuters was not immediately able to confirm Arestovych’s comments or independently verify the casualty numbers or other details of the incident.

Information from Reuters, Agence France-Presse and The Associated Press was used in this report.