Two moorings of a Caspian Pipeline Consortium loading facility and two berthed tankers were struck by drones on Sunday, prompting the suspension of loading, according to a post by CPC on the Telegram messenger service.
Fire broke out on one tanker, the Asia, and was later extinguished by the CPC emergency response teams. It was carrying oil from Tengizchevroil/Chevron. The Nissos Ios was carrying oil from Kashagan BV and Maten/NC KazMunayGas.
In a subsequent post on Monday, CPC said that a further attack took place on a vessel during loading. A fire broke out on the vessel, the Nelsa, but was later put out. The crew were unharmed, it said and loading has been suspended since.
There were no injuries reported from the attacks and no spillage of oil. The tankers remain afloat and damage assessments are taking place, the post said.
The CPC is a venture between energy companies from Russia, the US, Kazakhstan and several Western European countries, the post said.
The 1,500 km pipeline transports oil from three large fields in Kazakhstan - Tengiz, Kashagan and Karachaganak further west to the Russian port of Novorossiysk where cargoes then set sail across the Black Sea.
The post, which made no mention of the attack's origin, described it as "terrorist" in nature and said it was also considered "an attack on the interests of the CPC member countries as well".
The attacks match a pattern of strikes by Ukraine on vessels carrying Russian crude after a significant improvement in its drone capabilities that have seen it step up counter-attacks on Russia in the latter's fifth year of invasion of its neighbor.
Russia is a major stakeholder in the CPC and the posts, in Russian, likely originated from that country given its description of the incident as terrorism and due to a reference to the other CPC participants, including Kazakhstan, as "foreign".
"We expect the CPC member states to condemn these attacks and, in strict adherence to international law, to devise practical measures to halt terrorist attacks on the infrastructure used to export hydrocarbons produced by international consortia within the territory of the Republic of Kazakhstan," the later post said.
Ukraine is now regularly attacking Russian oil refining facilities to the extent that fuel shortages are now widespread across Russia and serious enough to deal a blow to the economy.
It handled 70.5 million tonnes of oil in 2025 with Chevron's (CVX) Tengizchevroil, ExxonMobil (XOM), NC KazMunayGas, Eni (E) and Shell (SHEL) accounting for more than 75% of this total, the post said.