Drivers in Russia's Saint Petersburg are facing long queues at petrol stations after weeks of intensified Ukrainian strikes on the country's energy infrastructure disrupted fuel supplies.

Ukraine has stepped up long-range drone attacks on Russian oil refineries, fuel depots and other energy facilities since early June, saying the campaign is aimed at disrupting Moscow's military logistics and reducing oil revenues that help finance its war effort.

At some filling stations in Saint Petersburg, signs indicated that 92 and 95 octane petrol was unavailable, while some stations were closed altogether.

Drivers told AFP they were spending hours searching for fuel and waiting in line to refuel.

"I drive a lot, I do about 500 km a day... Now I have to refuel every single day... because I have to stand in line at gas stations for an hour and a half, two hours, or even longer, and there’s no guarantee they’ll even have the type of gas I need," one driver said.