Reporting on what they’ve seen on April 13th, OSCE published a very long list of Russian hardware in eastern Ukraine. First up, near civilian houses, they saw Russian led forces firing a mortar into the town of Avdiivka. Yasynuvata is on the edge of the Russian occupied city of Donetsk.
Then, as the below screen grab of their report shows, they go onto detail the number of Russian tanks, artillery, Grad rocket launchers, anti-aircraft systems and armoured fighting and personnel carrying vehicles which they observed. Bearing in mind, this is just a handful of locations, they list a total of 90, Russian tanks.