Kremlin says it will reinforce borders including nuclear weapons if Sweden and Finland join Nato. Plus, Islamic State ‘Beatles’ member convicted

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Russia’s Black Sea flagship missile cruiser, the Moskva, has sunk while being towed to a port after an explosion, according to the Russian defense ministry.

Is Russia’s claim about a “storm” true? The claim of bad weather being a factor was questioned by observers. “Looking at the weather report outside of Sevastopol today the winds were about 4 mph with 40-degree [4C] temperatures and a little bit of rain,” the former commanding general of the US army in Europe told CNN.

What’s the significance? The sinking of the Moskva – the pride of its fleet and the most prestigious vessel involved in the war against Ukraine – represents a symbolic blow to the Kremlin.

What could this mean for Russian strategy? The CIA director, William Burns, warned of “desperation” from the Russian president, Vladimir Putin, who could resort to using a tactical or low-yield nuclear weapon as a result of his country’s military setbacks.

What should we expect next as the war enters its seventh week? Ukraine is braced for a powerful attack in the east.

What sanctions is Volodymyr Zelenskiy calling for? The Ukrainian president this week has been urging the west for greater sanctions such as to stop buying all Russian oil. He also wants diplomats to return to Kyiv.

Volodymyr Zelenskiy calls for European Union to impose embargo on Russian oil. Plus: our food system isn’t ready for the climate crisis

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The flagship of Russia’s Black Sea fleet has been severely damaged, Moscow has said, following an explosion that Ukraine claimed was due to a missile strike. The entire crew was evacuated.

The Ukrainian president, Volodymyr Zelenskiy, called for an oil embargo on Wednesday, demanding EU states “stop sponsoring Russia’s military machine”.

The US president, Joe Biden, announced a further $800m in military assistance to Ukraine as the country prepares for Russia to ramp up its efforts in the country’s eastern regions.

What will happen to the officer? He is on paid leave during the investigation.

Where did the footage come from? Lyoya’s passenger, the officer’s body-worn camera, the patrol car and a doorbell camera.