Oil exports via the Caspian Pipeline Consortium, which brings crude from Kazakhstan to a Russian terminal in the Black Sea, dropped by 24 per cent in December from the previous month following drone attacks, an industry source familiar with the data told Reuters on Friday.

CPC handles around 1.5 per cent of global oil and accounts for 80 per cent of Kazakhstan’s oil exports.

Shareholders in CPC’s 1,500-km (930-mile) pipeline include Kazakhstan’s state-owned oil company Kazmunaygas, Russia’s Lukoil and units of US oil giants Chevron and ExxonMobil.

Exports declined in December from November to 3.98 million tonnes, or around 1.02 million barrels per day, according to the source.