Kazakhstan has reduced crude oil production following drone strikes on commercial tankers at the Caspian Pipeline Consortium (CPC) terminal off Russia’s Black Sea coast, the country’s energy ministry announced Thursday.

“Oil firms adjusted their daily output, causing a temporary drop in production volumes,” the ministry said in a statement.

Kazakh officials described the reduction as a “purely technical” decision made to prevent storage tanks from overflowing after CPC restricted incoming oil shipments. Industry sources told Reuters this week that oil reservoirs at the terminal had reached capacity.

CPC suspended oil loadings at the Black Sea port on Monday following drone strikes on tanker ships. Russia accused Ukraine of targeting the vessels to disrupt global oil markets. Officials in Kyiv have not commented on the attacks.

Reuters reported that at least five tankers have been attacked at the CPC terminal so far in July.