Russia’s Rosneft-owned oil refineries in the Volga cities of Syzran and Saratov have stopped processing crude following Ukrainian drone attacks this month.

Axar.az reports, citing Reuters, that the Syzran refinery halted operations on Tuesday, while the Saratov plant stopped processing on September 11.

The shutdowns are expected to further complicate fuel shortages in Russia, which has restricted exports of gasoline, diesel and jet fuel.

Several facilities at the Syzran refinery were damaged in the September 15 drone attack, including its main CDU-6 crude distillation unit, which accounts for about 71% of the plant’s processing capacity. Sources said repairs could take at least a month.

The refinery’s second crude distillation unit was already undergoing repairs following a drone attack in July.

The Saratov refinery also suffered damage and fires in an earlier drone attack on September 8 and had been preparing to resume operations before the latest shutdown. The plant had previously remained closed for several weeks after an August 2 drone attack.