Azerbaijan and Armenian forces engaged in fierce clashes Sunday when a decadeslong conflict over disputed land erupted into renewed war involving tanks, artillery and aircraft.
Russia and international organizations including NATO, the European Union and the OSCE called on both sides to halt fighting over the territory of Nagorno-Karabakh. Turkey backed its ally Azerbaijan and said it was ready to offer assistance.
Armenian Prime Minister Nikol Pashinyan declared martial law and ordered a general mobilization, after accusing Azerbaijan of “preplanned aggression.” Azeri President Ilham Aliyev, who also announced martial law, said in a state TV address that Armenian forces were occupying Azerbaijan’s territory and “we’ll put an end to this occupation.”
Conflict has broken out repeatedly since Armenians took control of Nagorno-Karabakh and seven surrounding districts from Azerbaijan in a war after the Soviet Union collapsed in 1991. Hundreds died in 2016 before Russia pressured both sides to resume a cease-fire it first brokered in 1994. Armenia and Azerbaijan clashed again across their state border in July.
The confrontation has the potential to drag in Russia and Turkey, adding to geostrategic tensions between them over proxy conflicts in Syria and Libya. Russia has a mutual-defense pact with Armenia and a military base in the republic, while Azerbaijan hosted large-scale joint military exercises with Turkish forces last month.
Russian President Vladimir Putin expressed “serious concern about the renewal of large-scale military conflict” and called for a halt to hostilities in a phone call with Pashinyan, according to a Kremlin statement.
“Turkey stands by its Azeri brothers with all its means,” Turkish President Recep Tayyip Erdogan said on Twitter after he spoke with Aliyev.
Russian Foreign Minister Sergei Lavrov discussed the fighting with his Turkish counterpart Mevlut Cavusoglu, the Foreign Ministry in Moscow said in a statement. Lavrov also spoke separately by phone with the Armenian and Azeri foreign ministers, emphasizing the need for an immediate cease-fire, the ministry said.
A BP Plc-operated oil pipeline runs less than 30 miles (50 kilometers) from the conflict zone and carries as much as 1.2 million barrels daily from Baku to Turkey’s Ceyhan. While it hasn’t been targeted in previous conflicts, the pipeline may be vulnerable to any shift in the fighting between Armenian and Azeri forces.
Despite decades of mediation by the U.S., France and Russia, the two sides have never signed a peace agreement. Armenia says the right of the internationally unrecognized Nagorno-Karabakh Republic to self-determination should be respected, while Azerbaijan says its territorial integrity must be upheld.
This time, Azerbaijan said it began a “counterattack” after accusing Armenians of firing on its military positions and civilian settlements near Nagorno-Karabakh. Armenia said Azerbaijan started bombarding along the contact line separating the two forces and shelled civilians including in the region’s capital, Stepanakert.
Armenia should “seriously discuss” recognition of Nagorno-Karabakh’s independence as a response to the renewed conflict, Pashinyan told lawmakers in parliament.
While it provides military and financial support to Nagorno-Karabakh, Armenia has held back from recognizing the territory’s independence through decades of talks led by the Organization for Security and Cooperation in Europe to try to negotiate a settlement of the conflict.
The OSCE called for a ceasefire and the resumption of negotiations. The North Atlantic Treaty Organization said it was “deeply concerned” by the fighting in a statement.
Pope Francis also called on the leaders of Armenia and Azerbaijan to resolve the crisis “not through the use of force and arms but through the means of dialogue and negotiation” in an address from the Vatican Sunday.
The Azeri army is using tanks, artillery, missile systems and aircraft against Armenian positions near the front line and deeper into Armenian-held territory, the Defense Ministry in Baku said in a website statement. As many as 12 Armenian anti-aircraft systems have been destroyed and one Azeri helicopter was shot down, it said.
Armenian forces hit four Azeri helicopters, 10 tanks and about 15 drones, Armenian Defense Ministry spokeswoman Shushan Stepanyan said.
At least 16 Armenian serviceman have died and more than 100 were wounded in the fighting, Nagorno-Karabakh Deputy Defense Minister Artur Sargsyan said in a livestream broadcast.
The conflict comes after tensions between the two sides rose sharply last week, when Aliyev alleged that Armenia was massing forces near Nagorno-Karabakh for a new war. Armenia dismissed the claim as groundless and accused Aliyev of preparing for a war.
The fighting “is a war against our independence, freedom and dignity,” Pashinyan said in a televised address to the nation. “The Armenian people are ready for that war.”
Azeri forces are “fighting on our soil, and have no claim to anyone’s land,” Aliyev said in his speech. “We’ll win because our cause is just.”