Russia’s foreign ministry said on Thursday it had sent a protest to Britain’s ambassador to Moscow after he was summoned to complain about the involvement of British specialists in a Ukrainian drone attack on Russia’s Black Sea fleet in Crimea, Reuters reported.

“In the approach, it was emphasized that such confrontational actions by the British threaten to escalate the situation and may lead to unpredictable and dangerous consequences,” the Russian Foreign Ministry reported.

Ambassador Deborah Bronnert arrived at the Russian Foreign Ministry shortly after 10:30 a.m. as several people chanted anti-British slogans and held placards reading “Britain is a terrorist state.” She left after about 30 minutes.

Russian Foreign Ministry spokeswoman Maria Zakharova said she would provide evidence to the British ambassador, who was summoned in connection with Saturday’s drone attack on the Crimean peninsula, which Russia illegally annexed in 2014.

Accusations of Russia

In the statement of the Russian Foreign Ministry, it is stated that Great Britain has been training the personnel of the Ukrainian services for some time, as well as divers to acquire “sabotage skills at sea”.

“There is information that the British Navy has also transferred a certain number of unmanned underwater vehicles to the Ukrainian side,” the report says.

Britain denies that it carried out the attack, but does not hide that it helped train and arm the Ukrainian Armed Forces.

After the drone attack, Russia temporarily suspended its participation in the UN-brokered agreement on the export of Ukrainian grain through the Black Sea.

Russia portrays Britain as a particularly treacherous Western power that President Vladimir Putin says is plotting to destroy Russia and its vast natural resources.