The only thing the OSCE documented in the article you cited was explosions in the region and a casualty in the government controlled areas from the attacks.
It does not support your (Russia’s, really) claim of a Ukraine-initiated escalation
On page 2, with the map of the Donbas, the vast majority of the explosions are in northwest Luhansk, NE of Luhansk city itself, and North of Donetsk....on the Separatist side of the line of contact.
It does not support your (Russia’s, really) claim of a Ukraine-initiated escalation