Crimea was one of Ukraine’s favorite beach holiday destination until Russia invaded it and took it over – with the support of many of Crimea residents. Russia annexed Crimea from Ukraine in 2014.

Crimea remained to be a popular tourist destination for Ukrainians, but even more so for Russians visitors. Passports for Ukrainians to visit this seaside resort are not mandatory.

The Black Sea region (Ukraine, Russia) has also been a hot spot of escalations between the two countries.

On Sunday the Russian Federal Security Service says that it has evidence that Ukraine is responsible for clashes between Russian and Ukrainian ships in the Black Sea.

The agency, known as the FSB, said in a statement Sunday night that “there is irrefutable evidence that Kiev prepared and orchestrated provocations … in the Black Sea. These materials will soon be made public.”

The Ukrainian navy says Russian ships fired on and seized two of its artillery ships Sunday following an incident near Crimea, which Moscow annexed from Kiev in 2014. A tugboat was also seized.

Russian Foreign Ministry spokeswoman Maria Zakharova said on Facebook that the incident was characteristic of Ukrainian behavior: provoke, pressure and blame for aggression.

Ukraine says that the number of boats hit by Russian fire has increased to two, with two crew members wounded, and that both vessels have been seized by Russia.

The Ukrainian navy made the announcement in a statement late Sunday. Russia didn’t immediately comment on the claims.

Hours earlier, Ukraine said that a Russian coast guard vessel rammed into a Ukrainian navy tugboat, resulting in damage to the ship’s engines and hull. The incident took place Sunday as three Ukrainian naval ships were transiting from Odessa on the Black Sea to Mariupol in the Sea of Azov, via the Kerch Strait.

The European Union has called on Russia and Ukraine to “act with utmost restraint to de-escalate” the situation in the Black Sea.

Ukraine says that three of its ships have been seized by the Russian coast guard, including two that were fired upon, and two crew members were wounded. Russia has blamed Ukraine for preparing and orchestrating “provocations.”

The EU, in a statement from foreign affairs spokeswoman Maja Kocijanic, also said that it expected Russia to “restore freedom of passage” through the Kerch Strait after Moscow blockaded it.