Azerbaijan said that its army posts in Nakhchivan Autonomous Republic came under fire by Armenian forces early Monday.
"On August 2, at about 03.27 a.m. (2327GMT), the Armenian armed forces' units from the positions near the Arazdeyen village of the Vedi region using small arms subjected to fire the positions of the Azerbaijan Army in the direction of the Heydarabad settlement of the Sadarak region of the Nakhchivan Autonomous Republic," the Defense Ministry said in a statement.
Azerbaijan reported no casualties and said it responded with retaliatory fire.
"Currently, the situation in this direction is stable, our units control the operational situation," it added.
Relations between the two former Soviet republics have been tense since 1991, when the Armenian military occupied Nagorno-Karabakh, also known as Upper Karabakh, a territory internationally recognized as part of Azerbaijan, and seven adjacent regions.
New clashes erupted in September 2020, and ended on Nov. 10 with a Russia-brokered cease-fire.
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During the 44-day conflict, Azerbaijan liberated several cities and nearly 300 settlements and villages from Armenia's nearly three-decade occupation.
The cease-fire is seen as a victory for Azerbaijan and a defeat for Armenia, whose armed forces withdrew in line with the agreement.
A joint Turkish-Russian center was established to monitor the truce. Russian peacekeeping troops have also been deployed in the region.