Combatant seen in graphic 12-second clip circulated on Telegram had initially been wrongly named Tymofiy Shadura

• Russia-Ukraine war – latest updates

Ukraine’s security services have concluded that the prisoner of war killed by Russian soldiers in a clip that spread quickly across Ukraine and much of the world is Oleksandr Igorevich Matsievskyi, bringing an end to the dispute over his identity.

In the graphic 12-second clip that first circulated on Telegram last Monday, a detained combatant is seen standing in a shallow trench smoking a cigarette. The soldier, in uniform with a Ukrainian flag insignia on his arm, says “Glory to Ukraine” and is then apparently shot with automatic weapons by a group of Russian soldiers.

Both sides claim hundreds of enemy troops killed in past 24 hours. Follow all the latest developments

The Turkish defence minister, Hulusi Akar, said on Sunday that he believed the deal allowing Ukrainian grain to be exported via the Black Sea will be extended from its 18 March deadline.

The initiative, brokered between Russia and Ukraine by the UN and Turkey last July, was intended to prevent a global food crisis by allowing Ukrainian grain blockaded by Russia’s invasion to be exported safely from three ports.

Zakharova’s statement is noteworthy and supports several of ISW’s longstanding assessments about deteriorating Kremlin regime and information space control dynamics. The statement supports several assessments: that there is Kremlin infighting between key members of Putin’s inner circle; that Putin has largely ceded the Russian information space over time to a variety of quasi-independent actors; and that Putin is apparently unable to take decisive action to regain control over the Russian information space.

It is unclear why Zakharova – a seasoned senior spokesperson – would have openly acknowledged these problems in a public setting. Zakharova may have directly discussed these problems for the first time to temper Russian nationalist milbloggers’ expectations regarding the current capabilities of the Kremlin to cohere around a unified narrative – or possibly even a unified policy.