An oil tanker chartered for loading oil at the Caspian Pipeline Consortium terminal off Russia's Black Sea coast was attacked and damaged by two drones on Friday, CPC said.
Sources told Reuters the vessel, the Suezmax-class Nordic Zenith, had been chartered by US oil major ExxonMobil.
CPC did not identify any party as responsible for the incident. The past week has seen a sharp escalation in attacks by both Russia and Ukraine on shipping in the Black and Azov seas, marking a new phase in a war that has until now mainly been fought on the ground and in the skies.
CPC said in a statement that a fire broke out on the Nordic Zenith but was later extinguished. It said nearby CPC vessels evacuated 13 crew members while nine others chose to remain on board.
"The tanker has been removed from the loading schedule and is unfit for mooring or loading operations at the CPC terminal," CPC said on its social media channel.
An Exxon spokesperson said the company does not discuss operational details for marine transportation. "ExxonMobil does not own or operate marine vessels, and transport activities are managed by independent vessel owners and operators."
The CPC is a 940-mile (1,510 km) oil pipeline connecting Kazakhstan's Caspian Sea oil deposits with Russia's Black Sea port of Novorossiysk. Oil loaded at Novorossiysk is then taken by tanker to world markets.
CPC accounts for about 80 per cent of Kazakhstan’s oil exports. Its operations have been disrupted at various points in the war by Ukrainian attacks on pumping stations in Russia and by drone strikes on the CPC loading terminal near Novorossiysk.
(Reporting by Reuters; writing by Mark Trevelyan; Editing by Louise Heavens and David Gregorio)