Ukrainian intelligence services and members of extremist organisations may be preparing acts of sabotage in Crimea, namely in the Kerch strait, and provocations against Russian and foreign ships visiting Crimean harbours, according to the chief of the border guard of the Federal Security Service of Russia (FS), general Vladimir Kulishov.
No evidence is provided to support the allegation. These affirmations are consistent with the recurrent Russian narrative of Crimea as legally "reunified" with Russia and Ukraine as a destabilizing force, and Russia's claims about the Azov Sea and the Kerch Strait incident. These messages have intensified after the hearing of the International Tribunal for the Law of Sea on May 10 about the detention of Ukrainian vessels in the Kerch Strait. Russia refused to take part in the hearing, saying that the court had no jurisdiction in this case, and is trying to change the framework by insisting in "provocations" by the other part. You can see other examples of this narrative here and here.