Following Ukrainian drone strikes on Aug. 26, Russia’s fourth-largest oil refinery and second-largest gasoline producer has once again halted crude oil ​processing, according to Reuters, citing three industry sources.

Ukrainian forces struck production facilities of the Lukoil-Nizhegorodorgsintez oil refinery, also known as NORSI, in Kstovo, Nizhny Novgorod oblast, on Aug. 26.

“The strike confirmed a hit on the target, followed by a fire on the territory of the plant,” Ukraine’s  General Staff said. “The extent of the damage is being clarified.”

The overnight attack damaged several processing units, inter-unit infrastructure, and general plant ​facilities, according to Reuters. It is unclear how long the site will be offline as repairs are conducted.

Lukoil, the owner of NORSI, now has all its major refineries in Russia offline because of Ukrainian attacks, according to Reuters.

The NORSI refinery has an annual processing capacity of around 17 million metric tons of crude oil. It also produces diesel fuel, jet fuel, lubricants, and other petroleum products, including supplies used by the Russian military.

The key facility lies nearly 800 kilometers (nearly 500 miles) from the Ukrainian border, and has been shut down several times in recent months due to Ukrainian long-range strikes.

Ukrainian attacks on July 3 halted production at the NORSI site. Previously, the facility was reportedly forced to shut down on June 24 following a drone attack.

Throughout the summer, disruptive Ukrainian attacks on Russian energy infrastructure have led to long lines at gas stations and fuel shortages across the nation.

Kazakh Energy Minister Yerlan Akkenzhenov announced on Aug. 25 that Kazakhstan is set to process Russian crude and send 70% of its diesel and gasoline output back to Russia to help with the shortage.