(Reuters) -Russian air defence units downed six Ukrainian drones headed for Moscow on Sunday, mayor Sergei Sobyanin said. Sobyanin, writing on the Telegram messaging app, said specialists were examining fragments of the drones near the Russian capital.

Ukraine said it struck a Russian air base on Saturday, while Russia continued to attack Ukraine with hundreds of drones overnight as part of a stepped-up bombing campaign that has dashed hopes for a breakthrough in efforts to end the more than 3-year-old war.

Ukrainian drones struck the city of Krasnozavodsk in Russia's Moscow Oblast on July 7, possibly targeting the Krasnozavodsk Chemical Plant, Russian independent media outlet Astra reported. The plant,