BREAKING: Ukraine's defense ministry has been given orders to withdraw Ukrainian forces from Crimea: acting presiden

Ukraine’s Defence Ministry has been given orders to withdraw Ukrainian forces from Crimea – acting President (Reuters)

MarketWatch reports that, Russian troops took control of a Ukrainian naval base in Feodosia, Crimea, on Monday, according to media reports. The attack was reportedly the third on a Ukrainian base in 48 hours, and leaves Russia with control of most of the country's military bases in Crimea.

A Ukrainian army officer told Reuters that his colleagues were unarmed when Russian forces entered firing automatic weapons and using stun grenades.

Up to 80 Ukrainian servicemen were affected, according to the Ukrainian defense ministry. 

The seizure comes as G7 leaders hold a summit and after a top NATO military commander warned of a threat from Russia to the eastern part of Ukraine.

President Barack Obama arrived in the Netherlands on Monday to discuss with six other world leaders how to punish Russia for annexing Ukraine's Crimea region, including possibly excluding Moscow from the G8 club of rich nations.