Four servicemen of the self-proclaimed Donetsk People’s Republic (DPR) were killed over the past week in shellings by Ukrainian forces, Daniil Bezsonov, a spokesman for the DPR’s defense ministry, said on Monday.

"Three our servicemen were killed on Sunday in the village of Leninskoye in the south of DPR as a result of shellings by Ukrainian forces. We offer our condolences to their families and call on international organizations, first of all, the Organization for Security and Cooperation in Europe (OSCE), to resolutely condemn the Ukrainian side’s criminal actions," the Donetsk News Agency quoted him as saying.

One more serviceman was killed by a Ukrainian sniper in the village of Kominternovo.

Earlier in the day, Ruslan Yakobov, who heads the DPR’s mission to the Joint Center for Control and Coordination (JCCC), said that as many as 30 ceasefire violations by Ukrainian troops had been reported during the past 24 hours.

The "back-to-school" ceasefire came into force in Donbass from midnight August 29. It was agreed upon by the Trilateral Contact Group on the settlement of the conflict in eastern Ukraine on August 22, ahead of a new academic year. The ceasefire was violated three hours after it came into effect as Ukrainian forces shelled Gorlovka’s suburbs.

Since the outbreak of the conflict in Donbass, the parties have agreed on more than 20 ceasefires. The longest one of them was reported in 2016 when the ceasefire held for six consecutive weeks. However, all efforts to establish lasting ceasefire have been failing so far.