Russia says air defence forces intercepted attacks over port city of Sevastopol; Putin says Russia will take ‘reciprocal’ action if devices used on his troops

• What we know on day 508 of the invasion

Former UK prime minister Tony Blair has said Ukraine has done an “extraordinary” job in defending their country but when asked what endgame looked like he said the path will be “extremely difficult”.

He told Sky’s Sophy Ridge on Sunday:

I think there are two issues … it’s extremely difficult to see how you get a solution to this unless it’s very clear that Ukraine has a clear path to European Union membership, and a clear path to Nato membership.

I think probably people will wait and see what happens after this Ukrainian counter offensive. The Ukrainians have done an extraordinary job in defending their country and by the way, defending us by defending their country, but I think it will be how you deal with those two issues together. This is going to be extremely difficult, but I do think once we take stock after the counteroffensive, we’ve got to see if there was a way to bring it to an end with a negotiated end to it.

Territory is going to be the most difficult thing because Ukrainians will never accept the territory that, from an international community point of view has being taken wrongly from them, should be left with with Russia.

Of course, if they are used against us, we reserve the right to take reciprocal action.

Kyiv reports fighting has intensified on eastern front, with its forces on defensive near Kupiansk

• Russia-Ukraine war – latest news updates

Ukraine said fighting had intensified on the eastern front as further details emerged about the number of Wagner troops who had relocated to Belarus.

“The situation has somewhat intensified in the east,” the Ukrainian deputy defence minister Hanna Maliar said. She added that Ukrainian forces were on the defensive near the eastern city of Kupiansk but making advances near Bakhmut.

Ukraine and Russia accuse each other of shelling civilians; Moscow issues criminal charges against seven in alleged plot to kill top Russian journalists

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Ukraine and Russia have accused each other of shelling civilians in a village in Zaporizhzhia after three people were wounded in attacks. The head of Ukraine’s presidential administration, Andriy Yermak, said Russian forces bombed the village of Stepnohirske using multiple rocket launchers, hitting an administrative building. Moscow-backed officials claimed it was Kyiv’s forces that shelled a school in the village of Stulneve and air defence forces intercepted a drone over the city of Tokmak. Both sides have denied targeting civilians.

Russia has issued criminal charges against seven people who planned to kill two prominent Russian journalists in an alleged Ukrainian-backed plot, according to the state-owned Tass news agency. Russia’s FSB security service detained an unspecified number of people who conducted reconnaissance near the homes and workplaces of journalists Margarita Simonyan, head of state media outlet RT, and Ksenia Sobchak, who ran against President Vladimir Putin in 2018. The FSB said detainees had admitted preparing attacks on the two women on behalf of Ukraine and had been promised a reward of 1.5m roubles for each one.

South Korea’s president, Yoon Suk-yeol, has pledged to increase his country’s humanitarian and non-lethal military assistance to Ukraine after a meeting with President Volodymyr Zelenskiy in Kyiv. Yoon said Seoul would “expand the scale of supplies from last year, when we provided materials such as helmets and bullet-proof vests”, adding that humanitarian aid would be increased to $150m in 2023, from $100m last year.

Vladimir Putin has said the main objective of the deal that allowed Ukrainian grain exports to resume was not achieved, in a call with his South African counterpart, Cyril Ramaphosa. The Black Sea grain deal that eased fears of a global food crisis sparked by the war in Ukraine is due to expire late Monday unless Russia agrees to renew it. “The main goal of the deal, namely the supply of grain to countries in need, including on the African continent, has not been implemented,” Putin said according to a Kremlin release.

Ukraine has criticised Bulgaria’s president over his remarks that Kyiv is to blame for Russia’s ongoing war and that supplying arms to Ukraine only prolongs the conflict. President Rumen Radev spoke about the recent Nato summit and said that he wanted “to make it clear that Ukraine insists on fighting this war … But it should also be clear that the bill is paid by the whole of Europe.” The embassy of Ukraine in Sofia rejected Radev’s stance that supplying arms to Ukraine fuels and prolongs the war, saying Kyiv was making all possible efforts to restore peace.

Ukrainians have reacted with bemusement, mild irritation and irony to UK defence secretary Ben Wallace’s comments that the country should be more grateful for the help it is receiving from the UK and other allies as it fights off Russian aggression. Kyiv previously regarded Wallace as a staunch supporter and friend. His remarks – on the second day of the Nato summit in Lithuania last week – mystified officials. “Whether we like it or not, people want to see a bit of gratitude,” Wallace said, asked about President Volodymyr Zelenskiy’s frustration at not being given a formal invitation to join Nato.

A large convoy carrying fighters from the Wagner private army was spotted entering Belarus from Russia early on Saturday, according to independent monitoring group Belaruski Hajun. At least 60 trucks, buses and other large vehicles crossed into the eastern European country accompanied by Belarusian police. Belarus’s defence ministry said it planned for the mercenaries and Minsk’s own armed forces to conduct joint military drills.

FSB says it has detained people carrying out reconnaissance near the homes of Margarita Simonyan and Ksenia Sobchak

• What we know on day 507 of the invasion

Russian president Vladimir Putin held a phone call with South African president Cyril Ramaphosa in which the two leaders discussed the Black Sea grain deal and an African peace initiative on Ukraine, the Kremlin said on Saturday.

On the grain deal, which expires on Monday, Putin reiterated to Ramaphosa that commitments to remove obstacles to Russian food and fertiliser exports had not yet been fulfilled, the Kremlin said.