Armenia said Wednesday that the number of its soldiers killed in border clashes with Azerbaijan had risen to three, in the most serious outbreak of fighting between the ex-Soviet adversaries in months.

Azerbaijan previously said one of its soldiers died in the fighting on Tuesday along the disputed and volatile border region, where tensions are still high in the wake of a war between the Caucasus nations in 2020.

Armenia’s defense ministry said in a statement Wednesday that the body of an Armenian serviceman was discovered with fatal gunshot wounds in the vicinity where “intense skirmishes” had erupted on the previous day.

Two soldiers wounded in the fighting were in a stable condition, the defense ministry added, AFP reported.

Both sides have accused the other of initiating “provocations” that sparked the exchange of fire that left one Azerbaijani soldiers and the three Armenian troops dead.

Armenia said earlier that its military had been targeted by artillery and drones in its eastern border area, a claim Azerbaijan denied.

The deaths represent a serious threat to a ceasefire implemented with Russia’s help in November 2020 that brought an end to six weeks of brutal warfare that claimed the lives of 6,000 people on both sides.

The war centered around control for Nagorno-Karabakh, a sparsely-populated and mountainous separatist region inside Azerbaijan that had been controlled for decades by Armenian fighters.

As part of the ceasefire agreement, Armenia handed back large areas that the breakaway region had controlled for decades, including Kalbajar, where Azerbaijan said its soldier had been killed in the recent escalation.