The UN Security Council expressed concern about the clashes after Secretary General Antonio Guterres called for the fighting to cease.
Armenia and Azerbaijan accused each other of shooting directly at each other’s territory and declined pressure to hold peace talks as their conflict over the Nagorno-Karabakh enclave threatened to turn into an all-out war.
Both countries reported Tuesday that they shot across their common border from the other side, far west of the breakaway Nagorno-Karabakh region, which saw fierce fighting between Azerbaijani and ethnic Armenian forces on Sunday.
The incidents signaled a further escalation of the conflict despite urgent appeals from Russia, the United States and others to cease fighting.
The conflict has rekindled concerns about stability in the South Caucasus and threatens to drag on in Turkey and Russia.
Azerbaijani President Ilham Aliyev, who spoke to Russian state television, completely ruled out any possibility of conversation. Armenian Prime Minister Nikol Pashinyan told the same channel that negotiations could not take place while the fighting continued.
Nagorno-Karabakh is a breakaway region in Azerbaijan controlled by ethnic Armenians and supported by Armenia. It broke up in a war of Azerbaijan in the 90s but is not recognized as an independent republic by any country.
Dozens of people have been killed and hundreds injured since clashes between Azerbaijan and ethnic Armenian forces erupted on Sunday.
After a closed session on Tuesday, the UN Security Council of 15 expressed “concern” about the clashes, condemned the use of force and supported a call by UN Secretary-General Antonio Guterres to end the fighting immediately.
Armenia further fueled tensions between the two former Soviet republics, saying a Turkish F-16 fighter plane shot down one of its fighter jets over Armenian airspace, killing the pilot.
It provided no evidence of the incident. Turkey refused the claim.
“Armenia should withdraw from the territories it has occupied instead of using cheap propaganda tricks,” said Fahrettin Altun, the top press spokesman for Turkish President Recep Tayyip Erdogan.
Earlier this week, Armenia accused Turkey of sending mercenaries to support Azerbaijani armed forces in the ethnic Armenian region.
Any descent into an all-out war could affect not only Turkey but Russia as well. Moscow has a defense alliance with Armenia, but also maintains close ties with Azerbaijan.
The Kremlin said President Vladimir Putin had spoken to Paschinyan by phone for the second time since the crisis began and all sides should take steps to de-escalate. No contacts between Putin and Aliyev were made public.
Moscow was in constant contact with Turkey, Armenia and Azerbaijan, and any talk of military support for opposing sides would only add fuel to the fire, it said.
Pashinyan told the BBC in an interview that the Azerbaijani armed forces shelled villages and towns in Nagorno-Karabakh and Armenia themselves on Tuesday.
“There are victims among both the military and civilians. Dozens are killed and hundreds are wounded, ”he said.
The Azerbaijani public prosecutor said 12 Azerbaijani civilians had been killed and 35 injured in an Armenian fire. The Azerbaijani side has not disclosed any military casualties.
Nagorno-Karabakh has reported the loss of at least 84 soldiers.
“What can I say? It’s a war. We hear air strikes several times a day and hide in air raid shelters,” Albert Voskanyan, a resident of the enclave’s capital, Stepanakert, told Reuters.
Armenian officials previously said a civilian was killed in an Azerbaijani attack on the Armenian city of Vardenis, more than 20 km from Nagorno-Karabakh. They said a bus caught fire in the city after being hit by an Azerbaijani drone.
The Azerbaijani Ministry of Defense announced that the Armenian army from Vardenis had shelled the Dashkesan region in Azerbaijan. Armenia denied these reports.