At least 16 people have been killed and more than 130 wounded when Russian drones struck an Ukraine shopping centre, an attack President Volodymyr Zelenskyy described as an "act of barbarism".Regional governor Oleksandr Hanzha said that 22 children were among the wounded in the daytime attack on the city of Kryvyi Rih, which is Zelenskyy's hometown."There are 29 people in serious condition, including five children," Hanzha said "We will definitely respond."In a separate attack on Friday, at least four people, including three children, were killed and a woman was wounded after a Russian drone strike in Ukraine's southern region of Mykolaiv, Ukrainian state media said on Telegram.Russia is escalating its air war on Ukraine as fighting on the battlefield grinds toward the 4-1/2-year mark