The Azerbaijani Defense Ministry said it lost 50 troops in overnight clashes with ethnic Armenian troops after Yerevan said that at least 49 of its soldiers were killed in the fighting — the deadliest since Armenia and Azerbaijan fought a six-week war in 2020 over the breakaway Azerbaijani region of Nagorno-Karabakh.

"Fifty Azerbaijani servicemen died as a result of Armenia's large-scale provocation," the Azerbaijani Defense Ministry said in a statement, referring to border clashes that erupted early on September 13.

Russia said it had brokered a cease-fire between the two sides, but Azerbaijan accused ethnic Armenian forces of violating the agreement.

"Despite the declaration of a cease-fire since 09:00 (0600 GMT), Armenia is intensively violating the cease-fire along the border by using artillery and other heavy weapons," Baku's military said.

Armenian Defense Ministry spokesman Aram Torosian denied the accusation, calling it "obvious nonsense." Torosian said the Azerbaijani armed forces had not stopped shelling the positions of ethnic Armenian troops, settlements, and infrastructure "for a single minute." But he said the shelling in some directions had significantly weakened.

Earlier, Azerbaijan's Defense Ministry said that its forces were responding to Armenian "provocation" and denied claims that they were hitting civilian infrastructure.

"Azerbaijani armed forces are undertaking limited and targeted steps, neutralizing Armenian firing positions," it said in a statement.

Azerbaijani Foreign Minister Ceyhun Bayramov spoke by phone with Russian Foreign Minister Sergei Lavrov, the Azerbaijani Foreign Ministry said.

Source: RFE/RL's Armenian and Azerbaijani services
Lavrov emphasized the need to avoid conflict in the region, as well as the importance of the full implementation of the declarations signed between the leaders of Azerbaijan, Armenia, and Russia ending the fighting in 2020.

Armenia appealed earlier to world leaders after Prime Minister Nikol Pashinian said Baku had attacked Armenia's positions overnight and that fighting was ongoing.

"For the moment, we have 49 (soldiers) killed and unfortunately it's not the final figure," Pashinian told parliament.

Calls For De-Escalation

U.S. Secretary of State Antony Blinken spoke by phone with Pashinian and Azerbaijani President Ilham Aliyev. His spokesman said Washington would "push for an immediate halt to fighting and a peace settlement" between the neighbors.

Blinken said he told Aliyev and Pashinian that the fighting was "in no one's interest" and "urged them to do everything possible to pull back from conflict and get back to talking about a lasting peace."

Blinken said there were "always concerns" about Moscow's role in the peace process but added: "If Russia can actually use its own influence to calm the waters…that would be a positive thing."

The Armenian government said earlier that it would invoke a cooperation agreement with Moscow and appeal to the Russian-led Collective Security Treaty Organization (CSTO) — a regional security bloc — as well as the United Nations Security Council.

UN Secretary-General Antonio Guterres urged Armenia and Azerbaijan to urgently de-escalate tensions, calling on the two sides "to exercise maximum restraint and resolve any outstanding issues through dialogue and within existing formats," according to spokesman Stephane Dujarric.

France will raise the clashes at the UN Security Council, the office of President Emmanuel Macron said.

The Kremlin said on September 13 that Russian President Vladimir Putin was doing everything he can to help de-escalate hostilities.

"The president makes every effort to contribute to the de-escalation of tensions at the border. These efforts continue," Kremlin spokesman Dmitry Peskov told a news briefing.

Asked whether Moscow intends to do something in connection with Yerevan's appeal for help to the CSTO, Peskov declined to give details.

"I would not like to say more now. Since the work, various agreements and so on, I would not like to announce something before the approval process is completed," Peskov said.

Turkey, Azerbaijan's traditional ally, blamed Armenia for the latest flare-up, urging Yerevan to "cease provocations" against Baku.

"Armenia should cease its provocations and focus on peace negotiations and cooperation with Azerbaijan," Foreign Minister Mevlut Cavusoglu tweeted after a phone call with Bayramov.

The CSTO, which includes Armenia but not Azerbaijan, met virtually on September 13 to discuss the situation.

After the meeting the press service of the Belarusian president reported that the secretary-general of the CSTO may go to the conflict zone. The trip was proposed as one of the steps that could be taken immediately to diffuse the situation.

CSTO Secretary-General Stanislav Zas would use the trip to prepare a detailed report. Another proposal would create a working group from the staff of the CSTO Secretariat and the CSTO Joint Headquarters to analyze the situation and develop proposals, a CSTO statement said.

With reporting by Reuters, AP, dpa, and AFP