At least six Russian regions have rolled out an odd-even gasoline purchase plan as long lines of motorists continue to inundate gas stations amid nationwide fuel shortages caused by Ukrainian drone attacks on oil refineries.

The central Oryol region was the first to introduce the license plate-based rationing scheme last month to cope with the growing fuel crunch.

Drivers with license plates starting with an odd digit are allowed to buy gasoline on odd-numbered days of the month. Those with license plates starting with an even digit — with zero considered an even number — are restricted to even-numbered days.

On Thursday, the Nizhny Novgorod region, the republic of Mordovia and the city of Astrakhan adopted the same odd-even rules, according to a tally by the exiled news outlet Meduza. The Pskov region joined the system on Friday, followed by the Lipetsk and Kirov regions, where the restrictions take effect on Saturday.

Reports indicate the Ivanovo, Tambov and Yaroslavl regions are also weighing similar rules.