The Russian army accused Ukraine Saturday of a "massive" drone attack on its Black Sea Fleet in Crimea, while Britain bluntly rejected Moscow's claims its specialists were involved.Sevastopol in Moscow-annexed Crimea, which has been targeted several times in recent months, serves as the headquarters for the fleet and a logistical hub for operations in Ukraine.The Russian army claimed to have "destroyed" nine aerial drones and seven maritime ones, in an attack in the port early Saturday. Moscow's forces alleged British "specialists," whom they said were based in the southern Ukrainian city of Ochakiv, had helped prepare and train Kyiv to carry out the strike. In a further singling out of the U.K.

— which Moscow sees as one of the most unfriendly Western countries — Moscow said the same British unit was involved in explosions oN the Nord Stream gas pipelines last month. Britain strongly rebutted both claims, saying "the Russian Ministry of Defence is resorting to peddling false claims of an epic scale."The British defense ministry said that this "invented story says more about arguments going on inside the Russian government than it does about the West."Moscow's military said ships targeted at their Crimean base were involved in a UN-brokered deal to allow the export of Ukrainian grain. Russia had recently criticized the deal, saying its own grain exports have suffered due to Western sanctions. Mikhail Razvozhayev, the Moscow-installed governor of Sevastopol, said Saturday's drone attack was the "most massive" the peninsula had seen. The city's services were on "alert," but he claimed no "civilian infrastructure" had been damaged. He called on residents of the city not to post videos of the incident on social media."It should be clear to everyone that such information is much needed for Ukrainian Nazis in order to understand how the defense of our city is built," he said.City authorities said that the harbor was "temporarily" closed to boats and ferries and urged people "not to panic."Attacks on Crimea, annexed by Moscow in 2014, have increased in recent weeks, as Kyiv presses a counter-offensive in the south to retake territory held by Moscow for months. Moscow-installed authorities in Kherson, just north of Crimea, have vowed to turn the city into a fortress, preparing for an inevitable assault. On Thursday, Razvozhayev said a thermal power station had been attacked in Balaklava, in the Sevastopol area. He claimed there was only minor damage and no casualties.

 In early October, Moscow's bridge linking Crimea to the Russian mainland — personally inaugurated by President Vladimir Putin in 2018 — was damaged by a blast that Putin blamed on Ukraine. The Russian fleet stationed in the port had also been attacked by a drone in August.

 Russia's allegations Saturday came as the Ukrainian army reported fighting in the Luhansk and Donetsk regions in the east, including near Bakhmut — the only area where Moscow's forces have advanced in recent weeks.

 Pro-Russian separatists fighting alongside Moscow also announced a new prisoner exchange with Kyiv, saying 50 will return home from each side. On the southern front, AFP journalists witnessed artillery battles in the village of Kobzartsi, the last settlement on the Ukrainian side before the line of contact with the Russians. "It can go wrong here.

But we know that they suffer much more on their side than on ours," said Oleksiy, a Ukrainian soldier in his 20s. Both sides were gearing up for the battle for the city of Kherson, the regional capital that fell to Moscow's forces in the first days of their offensive.