Unverified reports and videos on social media suggested that a Lukoil-operated oil refinery in Volgograd also caught fire during the overnight attacks.
Tuapse has been under a state of emergency since late April, when successive waves of drone strikes sparked major fires at the Rosneft-operated oil refinery.
Satellite imagery reveals an increase in defensive construction at airfields including Khalino in the Kursk region and the Saki airbase in annexed Crimea.