MOSCOW — Ruzanna Avagyana, a 53-year-old social worker from the ethnic Armenian enclave of Nagorno-Karabakh, was taking stock Monday of the region’s rapidly escalating military conflict with Azerbaijan from inside her basement.
The fighting, the worst in Nagorno-Karabakh since a vicious ethnic war erupted in the region in the early 1990s, began a week ago and drove Ms. Avagyana underground.
She counted a half-dozen or so explosions in each of the first days she hid out in the basement, more on Sunday and so many on Monday she could hardly keep track. Then the apartment building on top of her took a direct hit.
“People are afraid,” Ms. Avagyana said in a telephone interview.
“I heard whistling this way and that,” she said, recalling the artillery strikes on her city, Stepanakert, earlier in the day. “I couldn’t understand where they were falling. And then I heard a boom.”
As her building burned, she escaped unharmed, Ms. Avagyana said.
Skirmishes have been common for years along the front lines of the Nagorno-Karabakh region, which is run by ethnic Armenian separatists but internationally recognized as a part of Azerbaijan.
But this conflict is distinct, analysts and former diplomats say, for the more direct support that Turkey has offered to Azerbaijan and for the scale of the fighting. Both sides have been using armed drones and powerful, long-range rocket artillery, they say. Turkey has denied offering anything more than training, weapons sales and political support to Azerbaijan.
Stepanakert, once a city of well-tended boulevards and stately stone homes, is now scattered with the ruins of bombarded buildings. On Monday, it came under heavy bombardment for a second day, Armenia’s military said.
On the Azerbaijani side, the authorities said rockets had landed in a residential area of Ganja, the country’s second-largest city. At least 250 people have died in the recent fighting, including dozens of civilians on both sides, according to official reports.
The long-range artillery fire of the type that destroyed Ms. Avagyana’s apartment building, which she said was across a street from a military headquarters and thus in a vulnerable location, has alarmed observers and former diplomats.
The weapons raise the risks of a direct conflict between Azerbaijan and Armenia, two former Soviet states divided by a poisonous and long-running ethnic dispute and competing claims to the Nagorno-Karabakh region.
So far, the fighting along the front has been muddled and inconclusive; reports from both sides are impossible to independently verify.
Azerbaijan has reported capturing, and then recapturing again, several villages in seesaw fighting over small strips of land. Those accounts have been denied by Armenia, which has accused the other side of targeting civilians and Turkey of shooting down one of its planes.
Both countries have in the past threatened to target strategic infrastructure with long-range weapons, raising worries that the conflict may intensify.
Over the weekend and on Monday, both sides fired large-caliber, Russian-made rockets of a type known as Smerch, or Tornado, saying they were aiming for military targets. Russia has for decades sold the same weapons systems to both parties to the conflict.
Nagorno-Karabakh vowed to fire back into Azerbaijan to retaliate for its shelling of Stepanakert.
“We are not targeting the civilian population but military facilities permanently deployed in large cities,” Vahram Poghosyan, a spokesman for the enclave’s president, told the Armenian news agency Arka. He said civilians should leave their homes to escape harm.
Rockets had already landed in Ganja, Azerbaijan’s second-largest city, on Sunday. Nagorno-Karabakh said it had fired at the city’s military airport, but photographs published in Azerbaijani media showed demolished houses.
A Russian television channel posted pictures of a Smerch rocket that did not explode sticking out of a parking lot of an Azerbaijani hydroelectric station at a jaunty angle, suggesting the targeting of strategic infrastructure.
Azerbaijan accused Armenia of firing the rockets from its territory, rather than from the disputed enclave, and said it was a tactic intended to provoke a retaliation that might trigger Armenia’s mutual defense pact with Russia. Armenia denied the charge.
The cause of the fighting is disputed. Azerbaijan said it responded to artillery fire across the frontline on Sept. 27. Armenia said the Azerbaijani offensive was unprovoked.
Armenia has said it is open to negotiating a cease-fire. Azerbaijan’s president, Ilham Aliyev, on Sunday told Al Arabiya television in an interview that the offensive would continue until Armenia withdrew support for the Nagorno-Karabakh enclave — something that is highly unlikely to happen.
“They must give us a timetable, or withdraw from the occupied territories,” Mr. Aliyev said. “Their prime minister who said ‘Karabakh is Armenia’ should now say that ‘Karabakh is not Armenia’ and after that, of course, we will be ready to put an end to hostility.”
Negotiating a cease-fire now will be harder than it was during a previous escalation in 2016, said Olesya Vartanyan, a Caucasus analyst with the International Crisis Group, because Azerbaijan felt misled by that settlement. After the 2016 escalation, Russia brokered a truce with an assurance to return to Azerbaijan some territory occupied by ethnic Armenians in the 1990s fighting, but that never happened.
“Even if Moscow calls on Baku to stop fighting, they have nothing to propose” now because the earlier promises never panned out, Ms. Vartanyan said, referring to the Azerbaijani government in the capital, Baku.
The bombardments suggest that a wider conflict between Armenia and Azerbaijan is possible, said Carey Cavanaugh, a former American ambassador and mediator in previous peace talks. “We can see in Syria how fragile cities can be” in artillery barrages, he said.
Wider fallout from the fighting may also be looming.
If Armenia targets oil and natural gas pipelines in Azerbaijan, neighboring Georgia could lose fuel just as winter sets in, Mr. Cavanaugh said.
There is also the risk of a coronavirus outbreak as troops hunker down in trenches and bunkers, he said. A deadly flu virus spread under such conditions in World War I.
And prolonged shelling could result in a flow of refugees as civilians flee the fighting, Mr. Cavanaugh said.
Ms. Avagyana has already left.
Moments after the explosion rocked her building Monday, the people huddling in the basement rushed out, she said. Smoke was billowing from a top floor.
She left Stepanakert later in the day, driving past a grocery store in flames and another apartment building with a gaping hole in it. Water from broken pipes was pouring through the ruined block, she said.
Though it is one of six unrecognized splinter states of the former Soviet Union, which are typically rundown places, Stepanakert had in recent years become a remarkably well- developed city. Money had poured in from the Armenian diaspora in the United States, France and Russia to help construct well-paved roads and presentable municipal buildings.
Seeing the city after the bombardments, Ms. Avagyana said, “was very painful.”