"The mortar was deployed at a distance of 5-6 kilometers (3-3.7 miles) [from the shelled area of Pervomaisk mine]. It means they [Ukrainian forces] did not withdraw mortars," Deinego said.
According to the republic's Emergencies Minister Sergei Ivanushkin, the mine was shelled at around 9:00 a.m. local time (7:00 GMT) Monday, damaging its water pump system.
Deinego added at a press conference that Kiev was exacerbating the humanitarian crisis in Luhansk by adopting a contrary stance.
The pullback of large-caliber weapons was outlined in the 13-point set of measures adopted a month ago to alleviate the Ukrainian conflict.
Later on Monday, however, Ukrainian military spokesman Andriy Lysenko expressed Kiev's refusal to "bare our frontline" by fully withdrawing military equipment.
Ukraine began waging a military campaign nearly a year ago against independence supporters that refused to recognize a new central government installed after a February 2014 coup.
Since then, the United Nations estimates more than 6,000 civilians have died from the violence.