Muscat: A fire at Russia's Tuapse oil refinery on the Black Sea coast, caused by a Ukrainian drone attack, has severely degraded air quality in the surrounding area. Russian firefighters have been battling the blaze for a third consecutive day following the strike, which took place on 16 April 2026. The Tuapse refinery, which exports most of its output, suspended operations after the attack. According to Oman News Agency, authorities in Russia's southern Krasnodar region said 276 firefighters and 77 vehicles were involved in the effort to extinguish the large fire. By-products from the blaze, mixed with rainwater, have formed a 'black layer' in areas around the refinery, they added.