American observer killed in Ukraine landmine blast
An American observer has been killed by a landmine which blew up a monitoring team vehicle in a separatist region of eastern Ukraine.
Two members of the Organisation for Security and Co-operation in Europe mission, from Germany and the Czech Republic, were wounded in the blast in Luhansk on Sunday .
Austrian foreign minister Sebastian Kurz, who holds the rotating chairmanship of the OSCE, called for an investigation and said on Twitter "those responsible will be held accountable".
In Washington, the US State Department expressed shock and sadness and extended condolences to family and friends of the victim, who was not identified.
Spokesman Mark Toner said the US "again calls upon Russia to use its influence with the separatists to take the first step toward peace to eastern Ukraine and ensure a visible, verifiable and irreversible improvement in the security situation".
He added: "This death underscores the increasingly dangerous conditions under which these courageous monitors work, including access restrictions, threats and harassment.
"The United States urges Russia to use its influence with the separatists to allow the OSCE to conduct a full, transparent and timely investigation."
The State Department said US secretary of state Rex Tillerson phoned Ukrainian president Petro Poroshenko to discuss his recent trip to Moscow and his message to Russia that Moscow's actions in eastern Ukraine remain an obstacle to improved relations with the US.
Mr Tillerson accepted Mr Poroshenko's condolences for the OSCE observer's death and the two leaders agreed that "this tragic incident makes clear the need for all sides - and particularly the Russian-led separatist forces - to implement their commitments under the Minsk Agreements immediately", the department said.
The self-proclaimed security ministry for the Russia-backed separatist rebels in Luhansk said the mine had been laid by Ukrainian forces.
The rebels and the Ukrainian government have been fighting in eastern Ukraine since 2014 in a war that has killed more than 9,900 people.
The monitoring mission assesses compliance with the two-year-old Minsk peace deal that was to bring a ceasefire and the pull-back of heavy weapons.
It also conducts work on human rights and civil society issues as well as mine-awareness programmes.