Armenia and Azerbaijan both reported casualties on Friday from fighting near their shared border, north of the breakaway region of Nagorno-Karabakh, according to Reuters.

Armenia's Defense Ministry reported that four of its soldiers were killed and another was injured in shelling near the border villages of Sotk and Norabak.

Azerbaijan's Defense Ministry said that Armenia had used drones to attack its positions across the border in the Kalbajar region, wounding three soldiers.

Defeat of Azerbaijani forces by the Armenian Army #Armenia #Azerbaijan #Sotk pic.twitter.com/uEjXBzbpnT

— Ararat Petrosyan (@araratpetrosian) September 1, 2023

The clash took place one day after Armenia accused Russia of "total disregard" for assaults on Armenian land.

Armenia alleged that Azerbaijan had assembled troops near the border and attacked its positions with drones, mortars, and small arms fire. Azerbaijan denied the accusation of troop buildup but said it was taking "retaliatory measures."

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Nagorno-Karabakh, an internationally recognized part of Azerbaijan populated mostly by ethnic Armenians, has been a source of conflict between the two Caucasus neighbors for over a century, dating back to the collapse of the Soviet Union in 1991.

Despite occasional talks on a peace agreement to resolve disputes and normalize relations, tensions remain high and border clashes are common. In two days of fighting in September of last year, around 300 soldiers were killed on both sides.

The ongoing fighting in the region has put a strain on the once-close relationship between Armenia and Russia, Armenia's traditional ally and the peacekeeper in Karabakh.

Armenia's Foreign Ministry said in a statement on Thursday that Russia had shown "complete disregard" for the attacks on Armenia's sovereign territory and had used a "pretext" to avoid supporting Armenia.

In recent months, Russia has expressed support for Azerbaijan's claim to Nagorno-Karabakh and has accused Armenia of maintaining a blockade of the separatist-controlled region. 

Read more: EU observers caught in crossfire on Azerbaijan border: Report