Updated

A member of the OSCE's monitoring mission in eastern Ukraine has died and at least one other was injured after their vehicle was blown up by a mine in the Luhansk region.

Austrian Foreign Minister Sebastian Kurz, who holds the rotating chairmanship of the Organization for Security and Cooperation in Europe, called for an investigation of the Sunday blast and said on Twitter that "those responsible will be held accountable." He said one mission member was injured, while officials of the Russia-backed separatist rebels, who hold much of Luhansk, said either one or three were injured.

The Luhansk rebels' self-proclaimed security ministry said the mine had been laid by Ukrainian forces that have been fighting the rebels for three years in a war that has killed more than 9,900 people.