Video report on YouTube on Apr 14, 2015 (read a report and view photos on Daily Mail, and read the eyewitness report on BBC.)
Members of an observation mission of the Organisation for Security and Cooperation in Europe (OSCE) and soldiers of the Donetsk Peoples Republic provided emergency first aid medical assistance to a journalist of the Russian TV channel “Zvezda” after he tripped a wire of a land mine in the village of Shyrokyne, on the Sea of Azov coast, near the city of Mariupol on April 14. Andrei Lenev suffered severe injuries to his head, legs and chest. Exchanges of gunfire happened following the accident, lending further credence to what the BBC reporter Tom Burridge description of the mine explosion as a “booby trap”.

The ambush took place during an inspection tour by the OSCE and the Joint Center of Ceasefire Coordination and Control. The JCCCC is the joint commission of Ukrainian and Russian militaries and the OSCE which was established last October to oversee implementation of the ceasefire.
Mariupol is under the control of extremist Ukrainian paramilitaries of the Azov Battalion and the regular armed forces of Ukraine. The city is app. 50 km west of the Russian border on the Sea of Azov.
Read also:
The OSCE Special Observation Mission report published on April 14, 2015 (information received as of April 13) contains extensive information on the escalation of attacks and provocations by the Ukrainian military and militias in several areas of the ceasefire demarcation line, including in the outskirts of Donetsk city.