The report is by Bellingcat, a "citizen investigative journalist" project that's funded in part by a Kickstarter campaign.
More from AFP:
Several columns of heavy armour on Monday headed through rebel-territory to the separatist stronghold of Donetsk in east Ukraine, an AFP journalist said, as fears mounted of a return to all-out fighting.
An AFP journalist saw a total of 21 trucks, six tanks and 14 howitzer cannons driving westwards in the direction of rebel frontline positions.
German Foreign Minister Frank-Walter Steinmeier says that the situation in Ukraine is "serious again" and that all sides, including Russia, must adhere to the terms of a September 5 truce agreement. -- REUTERS