Monitors recorded the use of small arms in the vicinity of Petrivske, the mission said in its daily report.
"On 29 October, positioned about 2 km north of Petrivske, the SMM heard shots and bursts of small-arms fire at an assessed range of 2-4 km south-west, assessed as inside the disengagement area," the mission said in its statement, without specifying which side opened gunfire.
Shots outside the disengagement area were also heard in the same locality, it said.
"Positioned at the same location and about 2 km north-east of Bohdanivka (government-controlled, 41 km south-west of Donetsk) the SMM heard 42 shots and bursts of small-arms and heavy-machine gun fire, as well as eight undetermined explosions, all assessed as outside the disengagement area, but within its 5 km periphery," the statement said.
However, a report of October 29 circulated by the headquarters of Kyiv's Joint Forces Operation says nothing of any shots near Petrivske, only mentioning truce violations near Bohdanivka, outside the disengagement area.
An uninterrupted seven-day ceasefire was named as the main condition for starting the disengagement of the sides' forces and military hardware in Donbas.
Ukrainian President Volodymyr Zelenskyi said on October 31 that the disengagement process in Petrivske is set to begin on November 4.
The sides started to disengage their forces and military hardware in Zolote, Luhansk region, on October 29.
Disengagement in Donbas is a condition for holding a summit of the Normandy Four (Ukraine, Russia, Germany, and France).