Armenia's military said on Monday that one of its soldiers was killed by sniper fire from across the border with Azerbaijan in the latest bout of deadly violence.
Border clashes erupted in mid-July between the ex-Soviet republics, which have for decades been locked in a conflict over Azerbaijan's breakaway region of Nagorny Karabakh.
Nineteen people -- including the Armenian soldier -- have been killed from both sides in the border clashes so far.
Armenia's defence ministry on Monday said that one of its troops was "killed by sniper fire from the direction of the enemy" overnight -- after a week of relative calm on the border.
Azerbaijan for its part accused Armenia of using "large calibre machine guns and sniper rifles" and violating a ceasefire multiple times along the border over the past 24 hours.
The uptick in violence has been unusual as it broke out hundreds of kilometres (miles) from Karabakh, Azerbaijan's southwestern region seized by ethnic Armenian separatists in a 1990s war that claimed 30,000 lives.
The recent violence has included artillery shelling and mortar fire, with both sides blaming one another and Azerbaijan threatening to strike Armenia's nuclear power station if its strategic facilities were attacked.
Regional powerbroker Moscow as well as Western powers have called for an immediate de-escalation amid fears that Russia and Turkey, which supports Azerbaijan, could be drawn into a confrontation.