Sumy and the surrounding region along the Russian border have long been subject to heavy attacks. A Russian drone strike on a shopping centre in the northern Ukrainian city of Sumy killed two people and injured 20, four of them seriously, Regional Governor Oleh Hryhorov said. Hryhorov, writing on Telegram, initially said three people had died but later corrected the death toll to two. He said a fire had broken out, and photos posted online by the governor showed a badly damaged building and rubble strewn on the ground. Four people were in serious condition, Hryhorov said. Four of the injured were teenagers, the national police said separately on Telegram. Across the wider region, five people were killed and 24 injured, the police added. Sumy and the surrounding region along the Russian border have long been subject to heavy attacks and Moscow has said it wants to establish a buffer zone in the area. Ukrainian ports under attack Russian air strikes hit Ukraine's port of Mykolaiv and civilian and industrial infrastructure there on Wednesday and overnight, killing four and injuring 19, Acting Regional Governor Heorhii Reshetilov said on Telegram. Russia's defence ministry said it also hit facilities used for military purposes in Ukraine's Black Sea port of Chornomorsk and two vessels near Odesa.