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

Three Ukrainian soldiers were killed in a landmine blast in the war-torn east, Kiev said Monday, as clashes between government forces and pro-Russian forces 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 kilometers (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 rebels' 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 Ukrainian military commanders will have to return previously withdrawn weapons to the contact line," he warned.