A Ukrainian drone attack on the Russian city of Nizhnekamsk in the Tatarstan region killed at least 12 people and wounded dozens more overnight Sunday into Monday, regional officials said. The strike hit the Nizhnekamskneftekhim petrochemical complex, one of Russia’s largest producers of synthetic rubber and plastics, according to Al Jazeera and the Moscow Times. Tatarstan sits roughly 800 kilometers east of Moscow and has rarely been struck this deep inside Russian territory.

Tatarstan’s health ministry said dozens of people were treated for injuries, with reported wounded figures ranging from 39 to 78 depending on the source. A child was reported among the dead, and citizens of Uzbekistan and Tajikistan working at the plant were also killed, the Moscow Times reported.

The strike was part of a broader wave of Ukrainian drone and missile attacks across Russian territory this week. Ukrainian President Volodymyr Zelenskyy said drones and missiles also hit a Russian naval base further south, striking air defense positions, piers and port infrastructure. Russian air defenses reported intercepting drones over Belgorod, Bryansk, Kaluga, Kursk, Lipetsk and Oryol regions, along with Crimea and the Black Sea.

The Nizhnekamsk attack ranks among the deadliest single Ukrainian strikes on Russian industrial infrastructure since the war began more than four years ago, according to Al Jazeera. Ukraine has increasingly targeted refineries and petrochemical plants that supply Russia’s military and export economy, arguing they are legitimate wartime targets given their role in funding the war.

Russian officials attributed the strike to Ukrainian drones but have not detailed the number or type used. Tatarstan’s regional government declared a period of mourning for the victims.

Kyiv has not publicly commented on the Nizhnekamsk strike specifically, consistent with its general practice of not claiming individual attacks on Russian soil. As of Wednesday, Tatarstan authorities said search and cleanup work at the petrochemical site had concluded, with the confirmed death toll standing at 12 and no additional casualties reported since Monday.