The cellular phone jamming system was discovered by observers of the OSCE Special Monitoring Mission in the south-western outskirts of Horlivka. This is stated in the report of the OSCE SMM.
"A military-type truck (Ural) with a mast-mounted cellular phone jamming system atop on the south-western outskirts of Horlivka (simultaneously, the SMM lost its connection to the Vodafone telecommunication network for about two hours, until it reached a different location about 2km east)", - the report noted.