Armenia has declared martial law and ordered the total mobilisation of its military after claiming to have destroyed several Azerbaijani aircraft and tanks in clashes over a disputed region on Sunday.
Armenia said Azerbaijan had carried out an air and artillery attack on the disputed region, Nagorno-Karabakh, but Azerbaijan said it had responded to Armenian shelling.
Human right activists in Armenia said two civilians – a woman and a child – had been killed by Azerbaijani shelling.
Officials in Baku, the Azerbaijani capital, said an unspecified number of their civilians had been killed and six wounded, and Nagorno-Karabakh said 10 of its military staff had been killed. The reports could not be independently confirmed.
The long-running dispute in the south Caucasus attracts regional and western concern because the area is a corridor for pipelines carrying oil and gas from the Caspian Sea to global markets.
Turkey has strong cultural and economic ties with Azerbaijan and has threatened to stand with it in any conflict.
Armenia’s defence ministry on Sunday said its troops had destroyed three tanks, and shot down two helicopters and three unmanned aerial vehicles in response to an attack on civilian targets including Nagorno-Karabakh’s capital, Stepanakert.
“Our response will be proportionate, and the military-political leadership of Azerbaijan bears full responsibility for the situation,” the ministry said in a statement echoed by the foreign ministry.
The Armenian prime minister, Nikol Pashinyan, wrote on Twitter: “We stay strong next to our army to protect our motherland from Azeri invasion.”
Azerbaijan denied the Armenian defence ministry statement, saying it had “complete advantage over the enemy on the front”, and accused Armenian forces of launching “deliberate and targeted” attacks along the front line.
“We defend our territory, our cause is right,” Azerbaijan’s president, Ilham Aliyev, said in an address to the nation.
The two former Soviet Republics have clashed for years over the mountainous region of Nagorno-Karabakh, a mainly ethnic Armenian territory that is officially part of Azerbaijan but which broke away from the country as the Soviet Union was dissolving.
Armenia and Azerbaijan fought a six-year war over the region until a ceasefire in 1994, and since then Nagorno-Karabakh has governed itself as the de facto independent Republic of Artsakh.
Both countries have continued to accuse each other of violating the ceasefire in the enclave and elsewhere along their border in the years since, including throughout 2020, with more than a dozen soldiers and civilians killed in fighting in past months.
At least 200 people were killed in a flare of the conflict between Armenia and Azerbaijan in April 2016.
Reuters contributed to this report