Azerbaijan launched “counter-terrorism measures of a local nature” in Nagorno-Karabakh on Tuesday, accusing Armenia of amassing troops in the disputed region. Yerevan has denied fielding any troops in the area, which is de jure considered to be part of Azerbaijan. 

Armenia accused its neighbor of starting “another large-scale aggression against the people of Nagorno-Karabakh”, and alleged Baku is seeking to subject the region, predominantly populated by ethnic Armenians, to “ethnic cleansing”.

Nagorno-Karabakh is internationally recognized as part of Azerbaijan but has been populated by ethnic Armenians.

In a statement, Iranian Foreign Ministry Spokesman Nasser Kana’ani on Tuesday expressed Tehran's deep concern over the latest flare-up between Baku and Yerevan in Nagorno-Karabakh.

“The Islamic Republic of Iran considers Karabakh as part of the Republic of Azerbaijan and believes that its issues, including the rights and security of its residents, should be resolved in this framework and through dialogue,” Kana’ani said.

The spokesperson once again stressed on the role of the countries in the region to help resolve disputes peacefully, while reminding the readiness of Tehran to host the 3+3 format cooperation mechanism in this regard.

The 3+3 format cooperation mechanism features the three South Caucasus countries of Armenia, Georgia, and Azerbaijan plus Russia, Turkey and Iran.

Officials in Nagorno-Karabakh have asked on Azerbaijan to implement a ceasefire and begin negotiations. At least 7,000 people from 16 villages in the mountainous territory had been evacuated following the military operation.

Twenty-five people have been killed as a result of an Azerbaijan’s military offensive, a separatist Armenian human rights official in the breakaway region of Nagorno-Karabakh told Reuters. Gegham Stepanyan has claimed 138 people, including 29 civilians, had been wounded.

The development came against a backdrop of decades of tensions between Armenia and Azerbaijan over the disputed Nagorno-Karabakh region on the border between the two countries.

The two Caucasian nations have been embroiled in a conflict over Nagorno-Karabakh since the late 1980s, when the predominantly ethnic Armenian region moved to break away from Azerbaijan and join Armenia. With the Soviet Union on the verge of collapse, tensions erupted into a major war in the early 1990s that claimed thousands of lives. The fighting ended with the signing of a ceasefire in 1994, although fighting has broken out sporadically since. 

One of the bloodiest clashes – which is often referred to as the Second Nagorno-Karabakh War – took place in 2020 and resulted in Azerbaijan taking control of a significant amount of territory. The hostilities ended in a Russia-mediated ceasefire. Since the truce, the two sides have accused each other of breaching the peace deal.

Earlier this year, however, both sides signaled a readiness to end the long-running territorial dispute.

Iranian officials have repeatedly stressed Tehran’s opposition to geopolitical changes in the region, and reaffirmed the country is ready to use all its capacities to establish peace in the Caucasus region and its growth and development.