Warehouses belonging to Russia's second-largest online retailer have been hit by a wave of Ukrainian drone strikes. Ozon said its logistics facilities in the southern regions of Krasnodar, Dagestan, Stavropol and Adygea were on fire and several people had been injured following overnight strikes.

Ukraine has for weeks struck sites belonging to Wildberries, the country's biggest online retailer, describing the firm as a legitimate target because it supplied components to the military, which Moscow denies. Russia has targeted Ukraine's civilian infrastructure since launching its full-scale invasion in 2022, and recent Russian attacks have hit Ukrainian warehouses and cargo terminals.

Both Russia and Ukraine deny deliberately targeting civilians. Ozon said "a fire broke out" at a logistics centre in Makhachkala, in the southern region of Dagestan, following a drone attack at around 05:00 local time (02:00 GMT) on Monday.

The company said earlier that a "major fire" was burning at one of its logistics centres in the city of Krasnodar, 700km (435 miles) to the east of the Dagestan site. Russia's defence ministry said three children had been killed in Krasnodar following a Ukrainian drone attack.

Russia's children's rights commissioner Maria Lvova-Belova said they were aged 13, 15 and 16, while six more children had been taken to hospital. Meanwhile, Ozon workers in Adygeysk, in the Adygea region, and Nevinnomyssk, in the Stavropol region, have been evacuated.

Videos posted on social media of the Ozon attacks have been verified by the BBC. One shows a drone hitting a warehouse in the Orenburg region, while another shows a large plume of smoke and flames rising from its warehouse in Dagestan.

The overnight strikes comes a day after Ozon's site in the Samara region was hit. The company said a number of its workers had been injured.

Following that strike, Ukraine's defence ministry said on Saturday: " Systematic strikes on dual-use goods storage centres complicate the enemy's logistics and negatively affect the Russian economy as a whole." After Ukrainian units hit 15 of the largest logistics hubs of Wildberries, it was Ozon's turn."

Meanwhile, in Ukraine's Odesa region, overnight strikes targeted food storage facilities and energy infrastructure leading to five people being injured, the region's head Oleg Kiper said on Telegram. Founded in 1998, Ozon is one of Russia's first online retailers.