Ukraine's largest steel company Metinvest said shells hit the territory of its Avdiivka coke plant on Sunday, damaging some of its facilities.
Earlier, the general prosecutor's office said five rockets had hit the plant, which had already suspended operations in the wake of Russia's invasion of Ukraine.
Metinvest, majority-owned by Ukraine's richest man and business magnate Rinat Akhmetov, said nobody was hurt in the shelling, which hit two coking shops and other areas.
