Three Ukrainian soldiers were killed in a landmine blast in the war-torn separatist east, Kiev said Monday, as clashes between government forces and pro-Russian insurgents rumbled on after more than two months of relative calm.


Over the last 24 hours a “radio-controlled landmine” laid by the rebels blew up some 50 kilometres (30 miles) southwest of insurgent stronghold Lugansk killing the three servicemen, military spokesman Andriy Lysenko said.


Lysenko said that the situation was “most tense” on the western outskirts of the separatists’ largest stronghold Donetsk, insisting that the “enemy regularly opens fire on our positions”.


“In case of further escalation of conflict … Ukrainian military commanders will have to return previously withdrawn weapons to the contact line,” he warned.


Meanwhile, separatist authorities accused the pro-Western Kiev army of breaching the truce 23 times, according to rebel-held news agency.


President Petro Poroshenko on Sunday decried a sudden re-escalation in the conflict with pro-Russian separatists after a Ukrainian soldier was killed in clashes in the country’s east.


Violence intensified in recent days with six soldiers killed over the weekend despite a September truce agreement.


The fighting had dropped to almost its lowest level since the start of the conflict following the start of the latest in a line of Western-brokered truces.


Over 8,000 people have been killed and more than 18,000 injured in Ukrainian conflict since April 2014, according to the United Nations.


Monitors from the Organisation for Security and Cooperation in Europe (OSCE) said over the weekend that the general situation in Donetsk region was “relatively tense”


The observers said they had recorded an increased number of incidents involving mines and unexploded ordnances.