Armenia and Azerbaijan Reach Cease-Fire After Russia-Brokered Talks

Azerbaijan and Armenia “are starting substantive negotiations with the aim of achieving a peaceful settlement as soon as possible,” Mr. Lavrov said, adding that the talks would be mediated by Russia, the U.S. and France.

Underscoring the precariousness of any truce in the volatile region, both sides accused each other of violating the cease-fire shortly after it took effect. Armenia said Azeri units launched an assault five minutes after 12 p.m. Azerbaijan, meanwhile, said that Armenian armed forces were firing on Azeri regions.

Roughly the size of Delaware, the territory of Nagorno-Karabakh—a disputed enclave controlled by ethnic Armenians but internationally recognized as a part of Azerbaijan—has been a flashpoint between the two countries since the years following the collapse of the Soviet Union. The fighting flared up last month after nearly three decades of on-again, off-again skirmishes. A six-year war ended with a 1994 cease-fire claimed some 30,000 lives.

Both sides have blamed each other for triggering the current outbreak of hostilities on September 27. Armenia said on Friday that 376 of its soldiers had been killed in the fighting so far while Azerbaijan hasn’t disclosed how many of its troops have been killed.

Authorities in Nagorno-Karabakh said the conflict so far has cost at least 22 lives and injured more than 80 people. Azerbaijan said 31 Azeri civilians have been killed and 168 have been injured.

For Russia, which has close ties with both Armenia and Azerbaijan and regards the former Soviet republics as part of its sphere of influence, a successful cease-fire would amount to a diplomatic feat and help solidify its role as a mediator in the region. It comes as a series of crises in Russia’s backyard, from Belarus in the west to Kyrgyzstan in the east, is upending the Kremlin’s plans for deeper economic and defense ties with the former Soviet republics.

The Kremlin has long worked to keep Armenia and Azerbaijan bound tightly to Moscow due to their strategic location along an important energy corridor coveted by the West. The truce announced Saturday follows phone calls this week between Russian President Vladimir Putin and the Armenian and Azeri leaders after which the Kremlin leader called for halting the hostilities on humanitarian grounds.

The truce comes after officials from the U.S., France and Russia, which have led mediation for almost three decades as co-chairs of the Organization for Security and Cooperation in Europe’s Minsk Group, have begun a concerted effort to reach a solution. On Thursday, diplomats from the trio met with Azerbaijan’s foreign minister in Geneva.

During the current flare-up in fighting, Turkey also intervened, throwing its support behind Azerbaijan, with which it shares ethnic and cultural ties. Turkey is already involved in two proxy conflicts with Russia—in Libya, where it is supporting the internationally recognized government against rebels backed by Russia, Egypt and the United Arab Emirates, and in Syria, where Moscow is a staunch ally of President Bashar al-Assad.

The Turkish government didn’t immediately comment on the cease-fire announcement. Earlier this week, Turkish Foreign Minister Mevlut Cavusoglu said a truce wouldn’t be enough to resolve the conflict because it would leave Armenia in control of parts of Azerbaijan’s territory.

“A cease-fire can take place, but what will be the result?” Mr. Cavusoglu said during a visit to Azerbaijan on Tuesday. “Can you tell Armenia to immediately withdraw from Azeri land?”

Since the conflict restarted, each side has accused the other of indiscriminate shelling of civilians and civilian infrastructure, including hospitals and schools, on both sides of the contact line that separates Armenian and Azeri forces. Roads, electricity and gas and communication networks have also been damaged across the region, officials from both countries say, though each denies targeting civilians.

Write to Georgi Kantchev at georgi.kantchev@wsj.com