As per UK Foriegn affairs press release, UK targeted Russion Oil trade and shadow fleet engaged in related oil transfers.
Today’s action also tightens the net around those enabling Russia’s illicit shadow fleet oil trade, hitting INTERSHIPPING SERVICES LLC, responsible for registering shadow fleet vessels under the banner of the Gabonese flag, resulting in these vessels transporting up to $10 billion worth of goods on behalf of the Russian state per year. Sanctions also target LITASCO MIDDLE EAST DMCC, which is linked to Russian oil major Lukoil, for its ongoing role in moving large volumes of Russian oil on shadow fleet vessels.
As per Intershipping website, they are sole Authorized Representative for Maritime Administration of Gabonese Republic worldwide. Below is quoted from thier website
“Intershipping Services is the sole Authorized Representative for Maritime Administration of Gabonese Republic worldwide.
It is based in UAE with its head office in Ajman, UAE, along with branch offices in Dubai, UAE, Piraeus, Greece.
His Excellency, Justin NDOUNDANGOYE, Minister of Transport and Logistics, and Mr. Hysham Shaikh, Director, Intershipping Services LLC signed the exclusive agreement of association on 15 September 2018 in Libreville – Gabonese Republic for the establishment and operation of the Gabonese International Register of Ships worldwide by Intershipping services”

As per ITF press release of 22nd May 2024, it was added in the list of FOC along with Eswatini. Below is quoted from ITF press release.
“The International Transport Workers’ Federation (ITF) adds two new countries to its longstanding list of Flags of Convenience.
Two ship registries strongly associated with ‘dark fleet’ transportation – Gabon and Eswatini – are the latest additions to the ITF’s Flags of Convenience (FOC) list.
The additions are accompanied by the removal of Tonga from the 76-year-old list, bringing the total number of FOCs to 43. “
Below screenshot of Gabon Flag circular will give clear relation between Gabon Flag registry and IS

Below link from IMO website also clearly establishes that ISS are acting on behalf of Gabon Flag
Full list of 135 Vessel can be found on below link
