Russia’s ministry of transport said on Thursday that restrictions on navigation at key Black Sea ports remain in place due to adverse weather.

Severe storms in the Black Sea region have disrupted up to 2 million barrels per day (bpd) of oil exports from Kazakhstan and Russia since last Friday.

“In the northern part of the Black Sea, unfavourable hydrometeorological conditions remain. In this regard, navigation restrictions continue to apply in the main seaports of Russia in the Black Sea basin until the weather improves,” the ministry said.

Separately, the Russian Federal Agency for Sea and Inland Water Transport (Rosmorrechflot) said that ferries across the Kerch Strait, which separates Russia for Crimea at the mouth of the Azov Sea, had resumed operations on Thursday morning.

Kazakhstan’s three largest oilfields cut their combined daily output by 103,800 metric tons on Wednesday because of the disruptions to shipping in the Black Sea, according to the energy ministry.

Production was down 67% at the Tengiz field, 65% at the Kashagan field and 34% at the Karachaganak field, the ministry said in a statement on Thursday.

Source: Reuters reported by Vladimir Soldatkin and edited by Mark Trevelyan and Kevin Liffey