Two oil tankers were attacked near the Black Sea loading terminal for the Caspian Pipeline Consortium, the latest significant incident complicating Kazakhstan’s crude exports.

The two ships — the Delta Harmony and the Matilda — were due to load barrels from Kazakhstan at the CPC offshore mooring, according to a person familiar with the matter, who asked not to be identified because the information isn’t public. Managers for both ships confirmed the incidents and said their ships had sailed away from the area. 

Prior to the attack, the vessels had moved away from the CPC facility, awaiting their turn to collect the cargoes, the person said. The extent of the damage to both ships wasn’t immediately clear. 

The attacks risk further disrupting loadings at CPC, where planned shipments have already plunged due to bad winter weather and mooring damage from a November drone strike. Those disruptions are helping dial back a significant surplus in the global oil market this quarter and have bolstered key futures prices. 

At times last year, CPC exported as much as 1.7 million barrels a day of crude, but loadings in January are set to be between 800,000 and 900,000 barrels a day this month. 

Kazakhstan’s energy ministry confirmed the incidents in a statement on Telegram. It said the Matilda suffered an explosion without a subsequent fire and no critical damages to its hull, while the Delta Harmony had a fire that was quickly put out, with no injuries to the crews of either vessel.

The press office of the Caspian Pipeline Consortium declined to comment. Thenamaris, which manages Matilda, said its ship was struck by an unspecified number of drones while outside the CPC Terminal. It suffered minor damage to the deck and remains fully seaworthy, the company said. 

Delta Tankers, which manages Delta Harmony, said its ship was hit by a projectile and a short-lived fire on board has been extinguished by the crew. The ship has shifted out of the high-risk area, they said. 

Chevron, which chartered one of the tankers, said the vessel involved remained stable and is proceeding to a safe port. There was no impact on its operations in Kazakhstan or exports, it added. 

Two additional tankers that were also reportedly hit appeared not to have been.

Ukrainian military officials declined to comment. In the past they confirmed involvement in attacks on tankers tied to Russia.

Cargo operations at CPC were halted over the weekend of January 10-11 due to bad weather, but Kazakhstan’s energy ministry said they were operating as normal on January 13. A vessel arrived at the port on January 12 and is expected to leave the following day, according to port agent data. 

The Matilda was set to load a cargo from the Karachaganak project, while the Delta Harmony was chartered to load crude from the Tengiz field, according to people familiar with the matter.

Neither ship loaded Russian oil since at least the start of 2021, according to vessel tracking data compiled by Bloomberg.

Attacks on oil infrastructure and tankers crossing the Black Sea have intensified over the past six weeks, with Ukraine launching salvos on a host of vessels linked to Russia, aiming to disrupt the Kremlin’s petroleum exports and cut the revenues used to fund the war. Kyiv says that Russia is also striking merchant ships.