KYIV -- The Ukrainian military has accused Russia-backed separatists in the eastern region known as the Donbas of violating a new cease-fire agreement shortly after it went into force.

The cease-fire, agreed by in talks including representatives of Russia, Ukraine, and the Organization for Security and Cooperation in Europe, took effect on March 5 just after midnight.

But Kyiv's headquarters for military operations in the east said that the separatists targeted government positions near the city of Shchastsya in the Luhansk region with grenade launchers, mortars, and other weapons at about 1 a.m.

It said that those attacks lasted about an hour and a half, and that separatists fired at another government position around daybreak.

The Ukrainian military said that its forces did not return fire.

The conflict in the Luhansk and Donetsk regions has killed more than 10,300 people since it erupted in April 2014, after Russia fomented unrest across much of Ukraine following the ouster of Moscow-friendly President Viktor Yanukovych.

It has persisted despite the Minsk accords, Western-backed cease-fire and peace deals signed in September 2014 and February 2015, and several additional agreements to cease hostilities.

With reporting by TASS