The Organization for Security and Cooperation in Europe (OSCE) has launched an internal investigation into a car explosion that killed an OSCE observer in separatist-controlled eastern Ukraine.
The OSCE Secretary-General Lamberto Zannier said on April 25 after talks with Russian Foreign Minister Sergei Lavrov that other investigations will also be launched to find out who is responsible for the April 23 explosion.
American paramedic Joseph Stone was killed and two other OSCE monitors -- a German woman and a Czech man -- were wounded when the car they were traveling in drove over a landmine on April 23.
"I'm now setting an internal investigation. There will be also a criminal investigation to understand who is responsible for this outcome," Zannier told reporters.
"A mine was left on a road which is also used by civilians, and there could have been other victims as well."
Lavrov said Moscow favors tightening the security measures for the OSCE's Special Monitoring Mission in eastern Ukraine.
The OSCE's mission has been set up to monitor the conflict between Ukraine's government forces and Russia-backed separatists in Ukraine's eastern Luhansk and Donetsk regions.
The conflict in Ukraine has killed more than 9,900 people since April 2014.