The affected plants have a combined nominal capacity of about 300,000 tonnes, or 2.2 million barrels, per day. Russia's total nominal primary refining capacity is estimated at roughly 930,000 tonnes per day.
In late October the refineries were processing about 700,000 tonnes of crude a day, the sources estimated. That figure has since fallen to 500,000 tonnes, about 10% below the September and October averages.
Among the hardest-hit facilities the sources named refineries in Ryazan, Yaroslavl and the Volga region. On Monday the strike hit Kirishinefteorgsintez, Russia's second-largest refinery. Alexander Drozdenko, governor of the Leningrad Region, said a fire broke out at the plant and one person was killed.
Deputy Prime Minister Alexander Novak said on October 30 that Kyiv had resumed strikes on Russian refineries after a pause. According to the agency, Ukraine had suspended attacks on energy infrastructure for two weeks.
Over the past weekend Rosneft reinstated fuel limits at its filling stations, capping purchases at 30 litres per customer within city limits.