The United Nations said it has confirmed at least 240 civilian casualties, including at least 64 people killed, in the fighting in Ukraine that erupted since Russia's invasion on Thursday - though it believed the "real figures are considerably higher" because many reports of casualties remain to be confirmed.

The U.N. Office for the Coordination of Humanitarian Affairs relayed the count late Saturday from the U.N. human rights office, which has strict methodologies and verification procedures about the toll from conflict.