YEREVAN, Armenia (AP) — Armenia and Azerbaijan blamed each other Monday for skirmishes on their volatile border that has left three Azerbaijani soldiers dead and several troops wounded on both sides.

The two neighbors in the Southern Caucasus have been locked in conflict over Nagorno-Karabakh, a region of Azerbaijan that has been under the control of ethnic Armenian forces backed by Armenia since a war there ended in 1994. International efforts to settle the conflict have stalled.

Armenian and Azerbaijani forces have frequently engaged in clashes. In 2016, scores were killed in four days of fighting.

The latest incident began Sunday when Armenian and Azerbaijani troops exchanged fire in the northern section of their border. Officials in both countries blamed each other for starting the fighting and said that sporadic shelling continued Monday.

Azerbaijan's Defense Ministry said that two of its soldiers were killed in Armenian shelling Sunday and another one later died in a hospital. It said five Azerbaijani servicemen were wounded.

Armenian Defense Ministry spokeswoman Shushan Stepanyan said Monday that two Armenian troops were wounded.

Armenian Prime Minister Nikol Pashinyan accused Azerbaijan of provoking the clashes and warned that it would “bear responsibility for the unpredictable consequences."

Azerbaijani President Ilhan Aliyev denounced what he described as “another provocation of Armenia” and vowed to protect Azerbaijan's national territory.