Kiev today announced a day-long halt to its deadly offensive to oust pro-Russian rebels in east Ukraine after fighting had stalled efforts by international investigators to kickstart a probe into the downing of Malaysia Airlines flight MH17.

International fallout from the crisis tearing apart the ex-Soviet nation rumbled on as the Group of Seven major developed economies warned Moscow that it could face even tougher sanctions over its backing for the insurgents, despite the EU and US already hitting Russia with the most punitive measures since the Cold War.

Dutch and Australian police experts were trying for the fifth day running to access the crash site of the downed Malaysian airliner after clashes between government and insurgent forces thwarted previous attempts to reach the scene.