Russians accused of barbaric behaviour apparently seen in videos and photos from captured city of Popasna

• Russian-Ukraine war – latest updates

Horrific video and photos have emerged that appear to show the head of a Ukrainian prisoner of war stuck on a pole outside a house in the eastern Ukrainian city of Popasna, which was captured by Russian forces in May and is close to the current frontline in the Donbas.

The Ukrainian governor of Luhansk province, Serhiy Haidai, posted the gruesome photo on his Telegram channel. It has since been widely shared on social media. Ukrainians have accused Russian troops of barbaric medieval behaviour and likened the image to Lord of the Rings.

Ukraine and Russia accuse each other of strikes at Zaporizhzhia nuclear plant; Putin and Erdoğan meet; three ships carrying grain depart Ukrainian ports

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Ukraine has accused Russian forces of strikes near a nuclear reactor at the Russian-occupied Zaporizhzhia power plant in the country’s south-east. Energoatom, the state-run operator of Ukraine’s nuclear power plants, said in a statement: “Three strikes were recorded on the site of the plant, near one of the power blocks where the nuclear reactor is located.” Russia’s defence ministry accused Ukrainian forces of shelling the plant, saying a leak of radiation had been avoided only by luck.

Vladimir Putin has met Recep Tayyip Erdoğan for talks that were expected to focus on Russia’s war in Ukraine and that are being rumoured to include Kremlin efforts to circumvent western sanctions. The Russian president welcomed Erdoğan to Sochi, a resort city on the Black Sea, by thanking the Turkish president for help in securing an international deal that resumed grain exports from Ukraine that had been disrupted by the Kremlin war machine – as well as Russian foodstuffs and fertilisers – to world markets. They agreed to boost cooperation in the transport, agriculture, finance and construction industries, they said in a joint statement after a four-hour meeting.

Three ships carrying almost 60,000 tonnes of grain between them have departed Ukrainian Black Sea ports and are on their way to Britain, Ireland and Turkey respectively. Oleksandr Kubrakov, Ukraine’s infrastructure minister, said he planned “to ensure ports have the ability to handle more than 100 vessels per month”.

Russia says it is ready to talk about a prisoner swap with the US following Thursday’s nine-year jail sentence for US basketball player Brittney Griner. However, the Kremlin said any such negotiations should not be played out publicly.

Amnesty International has said it stands by its accusation that Ukraine is endangering civilians by creating army bases in residential areas to counter Russian forces, after a report from the rights group prompted a furious response from Kyiv. Volodymyr Zelenskiy, the Ukrainian president, criticised Amnesty over the report published on Thursday, saying the rights group was drawing a false equivalence between Ukraine as the victim of aggression and the Russian invaders.

The UK’s Ministry of Defence has raised concerns about the “security and safety” of the Zaporizhzhia nuclear plant, saying Russia has “used artillery units based in these areas to target Ukrainian territory on the western bank of the Dnipro [Dnieper] river”.

A European Union plan to cut gas use and help Germany wean itself off dependency on Russia will come into effect early next week, the bloc’s presidency said on Friday. Last week, EU member states agreed to reduce their use of gas by 15% over the winter, with exceptions for some countries and despite opposition from Hungary.

Canada is sending up to 225 Canadian armed forces to the UK to recommence the training of Ukrainian military recruits, the Canadian defence minister has announced. Since 2015, Canada has trained 33,000 Ukrainian military and security personnel but in February paused aspects of the training.

A US official has accused Moscow of preparing to plant fake evidence to make it look like the recent mass killing of Ukrainian prisoners of war in an attack on a Russian-controlled jail was caused by Ukraine. Kyiv and Moscow have traded blame over last week’s strikes on the prison in Kremlin-controlled Olenivka, in eastern Ukraine.

A leading Russian hypersonics expert has been arrested on suspicion of treason, the state-controlled Tass news agency reported on Friday. Andrei Shiplyuk heads the hypersonics laboratory at the Novosibirsk Institute of Theoretical and Applied Mechanics, according to the institute’s website, and has in recent years coordinated research to support the development of hypersonic missile systems, Reuters reports.

Three grain ships leave Ukraine as Russia signals it is ready to talk about a prisoner swap with the US after Brittney Griner sentencing

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Three ships carrying almost 60,000 tonnes of grain between them have departed Ukrainian Black Sea ports and are on their way to Britain, Ireland and Turkey respectively. Oleksandr Kubrakov, Ukraine’s infrastructure minister, said he plans “to ensure ports have the ability to handle more than 100 vessels per month”.

Russia says it is ready to talk about a prisoner swap with the US following Wednesday’s nine-year jail sentence for US basketball player Brittney Griner. However, the Kremlin says any such negotiations should not be played out publicly.

Ukrainian president Volodymyr Zelenskiy has criticised a report by Amnesty International – which suggested Ukrainian forces’ tactics are endangering civilians by using some schools and hospitals as bases. Zelenskiy said the report “cannot be tolerated” as there “cannot be any condition under which any Russian attack on Ukraine becomes justified”.

The UK’s Ministry of Defence has raised concerns about the “security and safety” of the Zaporizhzhia nuclear power plant, which is under Russian control. It says Russia has “used artillery units based in these areas to target Ukrainian territory on the western bank of the Dnipro river”.

Vladimir Putin and Tayyip Erdoğan are due to meet in the Black Sea resort of Sochi. Talks between the presidents of Russia and Turkey are expected to focus on Syria, Ukraine and the Russian construction of a nuclear power plant in southern Turkey.

Canada is sending up to 225 Canadian armed forces to the UK to recommence the training of Ukrainian military recruits, the Canadian defence minister has announced. Since 2015, Canada has trained 33,000 Ukrainian military and security personnel but in February paused aspects of the training.

A US official has accused Moscow of preparing to plant fake evidence to make it look like the recent mass killing of Ukrainian prisoners in an attack on a Russian-controlled prison was caused by Ukraine. Kyiv and Moscow have traded blame over the strikes on the prison in Kremlin-controlled Olenivka, in eastern Ukraine, last week.

Ukraine has ceded some territory in the Donbas region to Russian forces, with Kyiv acknowledging Russia’s “partial success” in recent days. Zelenskiy has described the pressure his forces are under in the east of the country as “hell”. They have recaptured two villages near the city of Sloviansk, according to Ukrainian general Oleksiy Hromov, but have been forced to abandon a coal mine regarded as a key defensive position as forces are pushed to the outskirts of Avdiivka.

Russia may launch an offensive in the southern Ukrainian region of Kherson to try to wrest back momentum from Kyiv and has been visibly building up forces, Hromov said on Thursday. Much of the region is already occupied by Russia after it captured areas at the beginning of its invasion, but Ukrainian forces have been developing a counter-offensive to regain territory.