Moscow, Dec 31 : At least 21 people, including three children, were killed and 110 others wounded in Ukrainian shelling on the Russian border city of Belgorod, official sources said on Sunday. Belgorod Governor posted on social media: "The number of dead has increased to 21 people, of whom three are children. 110 people were injured with varying degrees of severity, including 17 children. To date, various damages have been identified in 30 apartment buildings, 344 apartments, three private households, several businesses and social facilities." According to a report from the Russian Defense Ministry, Belgorod and the region were shelled by the Armed Forces of Ukraine on Friday and Saturday. The last one was carried out by two rockets with cluster munitions and from a multiple launch rocket system to the city center, Xinhua news agency reported. The ministry said that the air defence systems intercepted rockets and most shells on Saturday and destroyed 13 rockets over the territory of the Belgorod region on Friday night. Meanwhile, citing an unnamed source in Ukraine's security services, Ukrainian local media reported that the Ukrainian forces struck Russian military facilities in the Belgorod region. The joint activities of Ukraine's defence forces continue as a "consequence of the Russian missile attacks on Ukrainian cities and the killing of civilians," the source said. On Friday, Russia launched massive air attack on Ukraine, killing 30 people and injuring 160 others, according to Ukrainian authorities. /IANS