MOSCOW, June 18 (Reuters) - Ukraine has been systematically targeting Russian energy infrastructure to try to disrupt Russia's economy and its ability to fund its military effort.

Ukrainian officials say attacks have been carried out in retaliation for Russian strikes on the Ukrainian energy system.

Following is a chronology of some of the main drone strikes on Russian oil refineries and infrastructure this year.

June 18 - A drone attack set ablaze oil storage sites in Russia's southern Rostov region.

June 14 - Debris from a downed drone damaged an unused reservoir at a fuel depot in Russia's Voronezh region.

June 6 - A fire was extinguished at the Novoshakhtinsk oil refinery in Russia's Rostov region which had been attacked by a drone.

May 20 - Slavyansk oil refinery was attacked by a drone.

May 18 - The Importpischeprom oil products terminal at Russia's Black Sea port of Novorossiisk resumed fuel loadings after suspending operations following a drone attack a day earlier, according to industry sources and LSEG data.

May 17 - Tuapse oil refinery on the Black Sea was attacked by drones for at least the second time this year.

May 12 - Volgograd oil refinery, which has a production capacity of some 300,000 barrels per day (bpd), caught fire following a drone strike.

May 10 - A drone attacked the Pervyi Zavod refinery in Russia's Kaluga region, following an earlier attack on March 15.

May 9 - Gazprom Neftekhim Salavat oil processing, petrochemical and fertiliser complex in the Bashkortostan region stopped its catalytic cracker after being attacked by a drone. The Salavat complex refinery runs were 130,000 bpd in 2023.

April 1 - A drone struck Russia's Taneco refinery. In 2023, it processed 340,600 bpd of crude oil, the third largest volume among Russian refineries after Omsk and Kirishi.

March 23 - A fire broke out at the Kuibyshev refinery after a Ukrainian drone attacked it. In 2023, it processed 73,700 bpd of oil.

March 18 - The Slavyansk refinery caught fire after a drone attack. It has a capacity of around 100,000 barrels per day.

March 16 - The Syzran oil refinery, controlled by Rosneft , burned for hours before the fire was brought under control after a strike by Ukrainian drones. The refinery has a production capacity of 170,000 bpd, but its actual runs have been lower. In 2023 it processed about 100,000 bpd.

March 15 - An oil refinery in the Kaluga region south of Moscow was attacked with drones, causing damage. Its primary processing unit's capacity is 1.2 million tons per year - roughly 24,000 barrels per day.

March 13 - The Novoshakhtinsk oil refinery, in Russia's southern Rostov region, suspended operations after downed drones crashed onto the site, but resumed operations later in the day. Oil processing at the refinery in 2023 averaged around 96,000 barrels per day.

March 13 - The Ryazan oil refinery was set ablaze after a drone attack. It's capacity stands at around 317,000 bpd.

March 12 - A drone was destroyed on the outskirts of Kirishi, home to Surgutneftegaz's Kirishinefteorgsintez (KINEF) refinery. The Kirishi complex is one of the top two refineries in Russia. It refines about 355,000 bpd of Russian crude.

March 12 - A fire broke out at NORSI, Russia's fourth largest refinery, after a drone attack. NORSI refines about 317,000 bpd of Russian crude a year. Lukoil also said in January that it had halted a unit at its refinery due to an unspecified incident.

Feb. 9 - A fire broke out at the Ilsky refinery in Russia's southern Krasnodar region and was extinguished in about two hours. Its refining capacity is 6.6 million metric tons of crude oil per year, equating to 132,000 bpd.

Jan. 26 - The Tuapse oil refinery in southern Russia halted oil processing and output following a fire. The Tuapse plant's capacity is 240,000 barrels per day.

Jan. 21 - Ust-Luga Complex was forced to suspend some operations at the huge Baltic Sea fuel export terminal at Ust-luga as well as "technological processes" at a nearby fuel-producing complex due to a fire, started by what Ukrainian media said was a drone attack. In 2023 the Ust-Luga complex processed 7 million tons of gas condensate (156,000 bpd). (Reporting by Vladimir Soldatkin, Editing by Timothy Heritage)