Russia has fired senior commanders who are considered to have performed poorly during the early stages of the Ukraine invasion, according to British intelligence.
Vladimir Putin is said to have axed two of his military leaders in relation to the failure to capture second city Kharkiv as well as the sinking of Moscow's flagship Moskva.
Lieutenant General Serhiy Kisel, who commanded the elite 1st Guards Tank Army, has been suspended, as has Vice Admiral Igor Osipov, who commanded Russia ’s Black Sea Fleet.
Russian Chief of the General Staff Valeriy Gerasimov, meanwhile, likely remains in a post, but it is unclear whether he "retains the confidence of President Putin", the intelligence says.
A statement from the Ministry of Defence adds: "A culture of coverups and scapegoating is probably prevalent within the Russian military and security system.
"Many officials involved in the invasion of Ukraine will likely be increasingly distracted by efforts to avoid personal culpability for Russia’s operational setbacks."
The 510-crew missile Moskva ship was struck by two Ukrainian missiles and was a major military blow for Russia.
Putin's nation still refuses to acknowledge that dozens and even hundreds of missing sailors on the ship are dead after it sank on April 14.
Kharkiv fell early during the war but in recent weeks, Russian forces have abandoned the area around the city.
"We have some success in these directions," Ukrainian President Volodymyr Zelensky's Chief of Staff Andriy Yermak told MSNBC this week.
It came as invaders across the country were forced to completely change tack after struggling to gain a central foothold as it moved in on Kyiv.
The capital city has always held firm and Kremlin fighters were eventually ordered to withdraw from the region to focus on the southeast.
However, despite several weeks of further bloody conflict on the new main front in the Donbas border region - which Moscow claims on behalf of separatists - it has made little headway.
Where Putin has seen rare success, is in Mariupol.
After months of daily shell attacks leaving the southern strategic port city almost completely in ruins, 700 Ukrainian fighters have this week surrendered allowing Russia to shore up control.
Kyiv has ordered its garrison in Mariupol to stand down, but the ultimate outcome of Europe's bloodiest battle for decades remains unresolved.
Moscow says it is engaged in a "special military operation" to demilitarise and "denazify" its neighbour.
The West and Kyiv call that a false pretext for invasion.
Around Slovyansk to the north of Donetsk, in the Donbas, Russian forces "suffered significant losses" around the settlement of Velyka Komyshuvakha, according to reports.
Ukrainian forces shelled a border village in Russia's western region of Kursk at dawn on Thursday, killing at least one civilian, regional Russian Governor Roman Starovoit said.
Ukrainian presidential adviser Oleksiy Arestovych said Ukrainian saboteurs had blown up railway tracks ahead of an armoured train carrying Russian troops in the occupied southern city of Melitopol.
