No - the Reuters article seems to contain the full detail of the allegations so far. There doesn't appear to be any detail released regarding the substance of these claims. The statement in question was posted on the Russian Ministry of Defence's Telegram channel:
Today at 4.20 am, the Kiev regime carried out a terrorist attack against the ships of the Black Sea Fleet and civilian ships that were on the outer and inner roadsteads of the Sevastopol base. The attack involved nine unmanned aerial vehicles and seven autonomous maritime drones.
❗️ It should be emphasised that the ships of the Black Sea Fleet that were subjected to the terrorist attack are involved in ensuring the security of the ‘grain corridor’ as part of an international initiative to export agricultural products from Ukrainian ports.
The preparation of this terrorist act and the training of military personnel of 73rd Marine Special Operations Center were carried out under supervision of British specialists 🇬🇧 in the city of Ochakov, Nikolayev region in Ukraine.
⚠️ According to the available information, representatives of this unit from the British Navy were involved in plotting, organising, and implementation of the terrorist attack in the Baltic Sea on 26 September this year to blow up the Nord Stream 1 and Nord Stream 2 gas pipelines.
The Russian Foreign Ministry Spokeswoman Maria Zakharova also made a statement on the matter, which is posted on the Ministry website (in Russian):
The Russian Foreign Ministry, together with the Russian competent departments, is working on practical steps in connection with the involvement of British specialists in the preparation of a terrorist attack in the Black Sea on October 29 and training of the Ukrainian military, as the Russian Ministry of Defense announced.
At the same time, the Russian military reported that they had information about the involvement of the British special services also in a series of explosions on the Nord Stream 1 and Nord Stream 2 gas pipelines in the Baltic Sea. Russia has repeatedly called for a joint investigation into these attacks. Relevant proposals were sent to the governments of Denmark, Sweden and Germany. The fact that the Western countries refused this proposal confirms that they have something to hide. Now we understand what exactly they are hiding.