At least 140,000 people have fled the conflict in eastern Ukraine in the last three weeks alone, with more than a million fleeing the region in total, according to figures published by the UN.
Nato has accused Russia of a “blatant violation” of Ukraine’s sovereignty by engaging in direct military operations to support the pro-Russian rebels in the east of the country.
A pro-Russian rebel leader has told Russian TV that thousands of Russian nationals have joined his forces to fight against the Ukrainian military.
The EU adopted a new range of economic sanctions against Russia over its involvement in the ongoing crisis in eastern Ukraine.
Heavy fighting between the Ukrainian military and pro-Russia separatists has prevented an international police force from reaching the crash site of Malaysia Airlines flight MH17.