Ukraine's interior minister has said that three tanks have crossed the border from Russia into rebel areas of the east and fighting is under way.
The tanks entered Ukraine along with other armour through a checkpoint controlled by rebels in the Luhansk region, Arsen Avakov said.
19:16 Analysis: Why are Russian warships in British waters?
22:36 Wary of Russian Guarantees, Residents Stay Put in War-Torn Aleppo
16:10 The Putin's 'Puppet' Accusations Speak Volumes About the Sad State of U.S.-Russia Relations11
00:18 Russia and Syria pause in bombing of rebel-held sections of Aleppo