Azerbaijan said it had destroyed an Armenian combat post in the south in retaliation for an earlier incident.
Last year Azerbaijan recaptured its Nagorno-Karabakh region held for decades by ethnic Armenians.
Armenia has now accused its neighbor of trying to escalate tensions.
The attack in Armenia’s south-eastern Syunik province also comes days after Azerbaijan’s President Ilham Aliyev won a fifth term in office, and local commentators have raised concerns that he may be considering further military action to seize Armenian territory.
