Amid renewed tension in eastern Ukraine, Russia has sent 15 warships to the Black Sea for a manoeuvre.
They passed through the Kerch Strait on the Crimean Peninsula on Saturday, the navy said, according to the Interfax news agency.
It was not initially said how long the exercises would last.
The United States had previously cancelled the deployment of two warships to the Black Sea following complaints from Russia, according to Turkish sources.
On Friday, the Russian Defence Ministry declared that certain sea areas in Crimea would be closed off for months because of the manoeuvres. However, shipping in the strait was not affected, it said.
The European Union, NATO and Ukraine criticized Russia’s actions. A senior EU official spoke of an “extremely worrying development.”
International concern is growing about an escalation of the conflict in eastern Ukraine because of Russian troop deployments not far from the Ukrainian border.
For almost seven years, parts of the Donetsk and Luhansk regions along the Russian border — collectively known as Donbas — have been controlled by separatists loyal to Moscow.
According to UN estimates, more than 13,000 people have been killed in the fighting. A peace plan agreed in 2015 with the help of Franco-German mediation is on hold.
Meanwhile, the head of Ukraine’s military operation, Sergei Nayev, indicated that he does not expect a new escalation.
“We don’t see any attack preparations there,” he told Ukrainian television on Friday night. “In fact, field hospitals have been set up.” All units are in camps, on firing ranges, he said. “In military language, we are talking about a show of force.”
Only on Friday, German Chancellor Angela Merkel and French President Emmanuel Macron had expressed concern about the Russian troop build-up along the Ukrainian border during talks with Ukrainian leader Volodymyr Zelensky and called on Moscow to withdraw.
Meanwhile, a Ukrainian diplomat has been arrested in the Russian city of St Petersburg. He had obtained classified documents, the domestic intelligence service FSB announced, which is not compatible with the status of a diplomat.