According to the OSCE Special Monitoring Mission January 22 report from the region, accompanied by an armed DPR member at the Olenivka checkpoint, OSCE monitors recorded two bullet holes on a passenger bus. The report also states that the monitors had earlier seen the bus about 50 meters south of the checkpoint, traveling north. The report estimates that the shots came from small arms fire from a western direction.

In a video posted by a crowd-funded journalist working on the separatist side, a DPR representative says the bus was coming from Ukraine and was en-route to Donetsk. It passed the gray zone and was at the DPR customs point (3:34-3:50), he also estimates that the bullets were 5.45 or 7.62mm. These are the calibers of the two most-commonly used types of Kalashnikov rifles with a one kilometer range.

On the same video Alexander Zakharchenko points to the west as the direction from where the shooting came.  According to the war zone map, area west of the Olenivka checkpoint is controlled by the DPR. Further debunking at Stopfake https://www.stopfake.org/en/fake-ukrainian-military-shoot-passenger-bus-in-donbas/.