Four Armenian separatist fighters died on Wednesday from Azerbaijani fire in the breakaway Nagorno-Karabakh region, the rebels said, as Baku and Yerevan held peace talks mediated by the United States.
Armenia and Azerbaijan have been locked in a decades-long conflict for control of the mountainous region in Azerbaijan, which is populated mainly by ethnic Armenians.
The clashes erupted a day after the United States opened three days of peace talks between the Caucasus arch foes, in the latest attempt to quell a conflict that has flared repeatedly.
On Wednesday morning, "units of the Azerbaijani armed forces opened fire with artillery" on Armenian positions, Karabakh's defence ministry said.
"Four servicemen were killed in action as a result of another provocation by Azerbaijan," it said, adding later that the situation along the border was now "relatively stable".
Armenian Prime Minister Nikol Pashinyan warned of a "high risk of destabilisation in the South Caucasus."
"I urge international community to take practical steps to ensure rights & security of Nagorno-Karabakh people," he said on Twitter.
There have been frequent clashes along the Armenian-Azerbaijani border, despite the two former Soviet republics trying to negotiate a peace agreement under mediation by the European Union and United States.
On Tuesday, Azerbaijan's defence ministry said "illegal Armenian armed detachments in the territory of Azerbaijan" opened fire at army positions, wounding one Azerbaijani serviceman.
The same day, US Secretary of State Antony Blinken opened closed-door negotiations with Armenian Foreign Minister Ararat Mirzoyan and his Azerbaijani counterpart Jeyhun Bayramov just outside Washington -- the second round of such talks he has led in as many months.
- 'Ethnic cleansing' -
Earlier this month, Pashinyan accused Baku of pursuing a policy of "ethnic cleansing" in Karabakh, saying traffic is being blocked through the Lachin corridor, the sole road linking the territory with Armenia.
The blockade followed a months-long roadblock by Azerbaijani environmental activists, which Yerevan claims has lead to a humanitarian crisis in the mountainous enclave.
Azerbaijan has insisted that civilians and aid convoys can travel through.
But the International Committee of the Red Cross said last week Azerbaijan had now blocked access for convoys delivering aid to Karabakh, raising fresh concerns over shortages of food and medicine.
Russia has been seen as the main mediator between the two former Soviet republics, but Brussels and Washington have been increasingly active, with Moscow bogged down in Ukraine.
Armenia has repeatedly accused Russian peacekeepers of failing to live up to promises to protect ethnic Armenians in line with a 2020 truce negotiated by Moscow after six weeks of fighting left thousands dead.
The ceasefire agreement saw Armenia cede swathes of territories it had controlled for decades.
When the Soviet Union collapsed in 1991, ethnic Armenian separatists in Karabakh broke away from Azerbaijan. The ensuing conflict claimed some 30,000 lives.
mkh-im/as/bp
