By Guy Faulconbridge and Vladimir Soldatkin
MOSCOW (Reuters) -A Ukrainian drone struck Russia's third-largest oil refinery on Tuesday about 1,300 km (800 miles) from the front lines, hitting a unit that processes about 155,000 barrels of crude per day, though an industry source said strike caused no critical damage.
A Ukrainian intelligence source said Ukraine hit the primary refining unit at the oil refinery in Russia's highly industrialised Tatarstan region and caused a fire. Such attacks are intended to reduce Russia's oil revenue, the source said.
Russian officials said jamming devices locked onto a Ukrainian drone near Tatneft's Taneco refinery, which has an annual production capacity of more than 17 million tons (340,000 barrels per day).
Pictures from the scene showed the drone hit the primary refining unit, CDU-7, though it did not appear to have caused serious damage.
The industry source, who spoke to Reuters on condition of anonymity, said personnel was returning to the plant.
A fire was extinguished within 20 minutes, the state news agency RIA said, adding that output had not been disrupted.
The affected unit accounts for around a half of the plant's total annual production capacity. The refinery represents about 6.2% of Russia's refining capacity.
Brent briefly rose above $89 a barrel for the first time since October amid concern over the Ukrainian drone attacks and the escalating conflict in the Middle East. [O/R]
Ukrainian President Volodymyr Zelenskiy made no direct reference to the Tatarstan attack, but said Kyiv's long-distance military action against Russia was important.
"Equally important is that the Russian terrorists are receiving responses to their strikes," he said in his nightly video address. "Each time, longer-range responses."
TARGETING OIL REVENUE
Another Ukrainian intelligence source said Ukrainian-made drones had also hit a Russian plant producing long-range Shahed attack drones, causing "significant damage".
The Washington Post (NYSE:POST) reported last year that Russia was mass-producing drones at a plant in Tatarstan.
Ukraine has in recent months begun attacking the oil refineries of Russia, the world's second-largest oil exporter, impacting Moscow's highly lucrative trade in refined products, amid extensive Russian missile strikes on Ukraine's energy grid.
According to Reuters calculations, around 14% of Russia's refining capacity has been shut down by drone attacks. There is more demand for refined oil products than for Russian crude.
The attacks on Russian refineries have raised concern in Washington about the potential for escalation with Russia.
Ukraine says its drone attacks on Russia are justified because it is fighting for survival and has suffered damage to its infrastructure from Russian air strikes.
Ukraine, which says it has been attacked by more than 4,630 Russian long-range Shahed drones during the 25-month-old war, regards its own drone production push as a way to hit back at a much better armed and larger enemy.
Since President Vladimir Putin sent Russian forces into Ukraine in 2022, drones have played a big part in the war - either as "kamikaze" attackers or as eyes in the sky that guide other weaponry to kill soldiers or destroy equipment.
Ukraine has carried out a series of high-profile attacks deep inside Russia meant to either undermine Russia's war machine or, as with a 2023 drone strike on the Kremlin, bring the reality of war to the very heart of Russia.
A powerful ally of Putin said on Tuesday that NATO was essentially fighting Russia in Ukraine and that the U.S.-led alliance had helped organise strikes on Russian territory.
When asked if Russia thought the United States was involved in the attacks on Russian refineries, Kremlin spokesman Dmitry Peskov said on Tuesday the question was better addressed to the defence ministry and security services.
"The Kyiv regime continues its terrorist activity," Peskov said. "We and our military are primarily working to minimise this threat, and subsequently to eliminate it."
Ukrainian sources say Kyiv alone is responsible for the planning and execution of drone attacks in Russia. The United States says it does not support Ukrainian strikes inside Russia.
Tuesday's attacks also hit enterprises in Yelabuga and Nizhnekamsk and some people were injured, Tatarstan's regional governor Rustam Minnikhanov said.
Two drones struck a dormitory on the territory of the Alabuga Special Economic Zone and at least seven people were injured, Russian media reported.