Servicemen and members of the Armenian Revolutionary Federation gather after the Armenian government declared martial law and military mobilization amidst growing conflict with Azerbaijan.

Caption

Servicemen and members of the Armenian Revolutionary Federation gather after the Armenian government declared martial law and military mobilization amidst growing conflict with Azerbaijan. / Melik Baghdasaryan/Photolure/TAS

Fighting broke out between Armenia and Azerbaijan in the disputed territory of Nagorno-Karabakh on Sunday, causing casualties on both sides and prompting the Armenian government to declare martial law and mobilize its military.

The conflict is the latest eruption of violence in a decades-long dispute over the region, which lies within the borders of Azerbaijan but is controlled by ethnic Armenian forces. Both countries have reported military and civilian deaths as of Sunday afternoon.

Armenian officials said Azerbaijani forces launched a "missile and aerial attack" in the region on Sunday morning, targeting peaceful settlements and shelling civilian infrastructures, while Azerbaijan's Ministry of Foreign Affairs said its armed forces were responding to Armenian shelling.

Armenian Prime Minister Nikol Pashinyan said in a tweet that the aggression seemed to be pre-planned, and "constitutes large-scale provocation against regional peace & security."

Azerbaijan's president, Ilham Aliyev, countered that "the first fire, including artillery fire, was opened by Armenia, and the first victims were Azerbaijani servicemen."

Officials in both Armenia and Nagorno-Karabakh declared martial law and dispatched armed forces as tensions rose on Sunday morning.

The human rights ombudsman of Nagorno-Karabakh said that a woman and child were killed and two civilians were wounded in the Martuni region as a result of Azerbaijani shelling. The region's deputy defense minister later said that 16 Armenian forces were killed and more than 100 were wounded.

Aliyev, Azerbaijan's president, said enemy fire had killed and wounded both servicemen and civilians, and that "shedding of their blood will not go unpunished."

"Armenia is an occupying state, and an end to this occupation must and will be put," Aliyev added.

Turkish President Recep Tayyip Erdogan, whose nation shares a border with Armenia, reinforced his country's support for longtime ally Azerbaijan in a series of tweets, in which he called Armenia "the biggest threat to peace and tranquility in the region."

"The Turkish Nation stands by its Azerbaijani brothers with all its means, as always," he wrote.

In response, Armenian prime minister Pashinyan issued a statement calling on the international community to "use all of its influence to halt any possible interference by Turkey," which he said would have devastating consequences for the region.

The renewed conflict threatens the stability of the southern Caucasus, which is crisscrossed by numerous oil and gas pipelines.

Reactions from the international community poured in on Sunday, with foreign leaders calling on the long-time adversaries to de-escalate the conflict and restart dialogue.

The Organization for Security and Co-operation in Europe's Minsk Group, co-chaired by the United States, Russia and France, has been working to permanently settle the dispute between Azerbaijan and Armenia since 1994. Its leaders issued a joint statement expressing concern about the reports of military actions and condemning the use of force and "senseless loss of life."

"The Co-Chairs call on the sides to take all necessary measures to stabilize the situation on the ground and reiterate that there is no alternative to a peaceful negotiated solution of the conflict," they added.

Separately, officials in Russia and France urged the countries to cease fire and begin negotiations immediately.

Charles Michel, president of the European Council, also called for a halt to military action and a return to negotiations "without preconditions."

Similar hopes were expressed at the Vatican, where Pope Francis urged leaders to find a solution "not through the use of force and arms, but through the means of dialogue and negotiation."

Azerbaijan and Armenia have clashed periodically in the wake of the 1994 ceasefire that left Nagorno-Karabakh in Armenian control. Notably, a wave of violence in 2016 killed at least 30 troops on both sides. And more recently, fighting along the border killed at least 16 people in July.

Copyright 2020 NPR. To see more, visit https://www.npr.org.

Correction

An earlier version of this story in one instance incorrectly referred to Armenian Prime Minister Nikol Pashinyan as the nation's president.