Dozens have been reported killed and more than 200 wounded in the fighting which broke out on Tuesday when Azerbaijan sent troops backed by artillery against separatists in the Armenian-controlled Nagorno-Karabakh region in the South Caucasus.

Nagorno-Karabakh is internationally recognised as Azerbaijani territory but part of it is run by separatist Armenian authorities who say it is their ancestral homeland.

The Russian foreign ministry said on Wednesday that Russia’s 2,000-strong peacekeeping mission in Nagorno-Karabakh was evacuating civilians and providing medical assistance amid the clashes.

“We urge the conflicting parties to immediately stop the bloodshed, stop hostilities and eliminate civilian casualties,” the ministry said in a statement.

The United States and France also called on Tuesday for Azerbaijan to halt its offensive against the Karabakh separatists who reported that 27 people, including two civilians, had been killed and more than 200 wounded.

Azerbaijanian officials in the capital Baku said fighting would continue until the separatists in Nagoro-Karabakh surrendered.

“Illegal Armenian armed forces must raise the white flag,” Azerbaijan’s presidency said. “Otherwise, the anti-terrorist measures will continue until the end.”

In Armenia’s capital Yerevan, angry protesters clashed with police in calling on Prime Minister Nikol Pashinyan to resign over his handling of the situation and the country’s security council warned of large-scale unrest.

“There is currently a real danger of mass turmoil in the Republic of Armenia,” the council said in a statement, promising to take “effective measures” to maintain constitutional order.

More than 30 people were injured in the clashes in Yerevan, the health ministry said.

The latest violence in Nagorno-Karabakh comes as Russia, the traditional power broker in the region, is bogged down in its war in Ukraine.

‘Illegal, unjustifiable and unacceptable’

The fighting erupted on Tuesday just hours after Azerbaijan said four police officers and two civilians were killed in land mine blasts in Nagorno-Karabakh, which authorities blamed on separatists.

Azerbaijani forces pounded the mountainous Nagorno-Karabakh territory with artillery, jets and drones on Tuesday, according to separatist authorities, who said that their stronghold, Stepanakert, had come under attack and that more than 7,000 people were evacuated from 16 villages.

French Foreign Minister Catherine Colonna told reporters that Azerbaijan’s operation was “illegal, unjustifiable and unacceptable”.

“I would like to emphasise that we hold Azerbaijan responsible for the fate of Armenians of Nagorno-Karabakh,” Colonna said.

US Secretary of State Antony Blinken spoke by telephone with Armenia’s Pashinyan and Azerbaijan’s President Ilham Aliyev. French President Emmanuel Macron also spoke with to Pashinyan.

I spoke to Azerbaijani President Aliyev today and urged him to immediately cease military actions in Nagorno-Karabakh. It is crucial for Azerbaijan to deescalate the situation to promote a peaceful resolution of the conflict.

— Secretary Antony Blinken (@SecBlinken) September 19, 2023

I spoke to Armenian Prime Minister Pashinyan today to express our deep concern about Azerbaijan’s military actions. The United States is calling for an immediate end to this unacceptable military action.

— Secretary Antony Blinken (@SecBlinken) September 19, 2023

Blinken urged Azerbaijan to “immediately cease military actions in Nagorno-Karabakh”.

“It is crucial for Azerbaijan to deescalate the situation to promote a peaceful resolution of the conflict,” US President Joe Biden wrote on social media, repeating his request made in a call with Aliyev, US State Department spokesman Matthew Miller said.

The ex-Soviet Caucasus rivals have fought two wars over the mountainous territory, in the 1990s and in 2020.

The latest offensive has raised fears that the unrest could destabilise the region.

Azerbaijan has justified the offensive military accusing the separatists of “a high level of combat readiness”.

Russia and Turkey, which oversee a fragile peacekeeping mission in Nagorno-Karabakh, had been informed about the Azerbaijan operation.

Turkey, a historic ally of predominantly Muslim Azerbaijan that views mostly Christian Armenia as one of its main regional rivals, called the operation “justified”, while urging “comprehensive negotiations”.

UN Secretary-General Antonio Guterres called for an immediate end to the fighting on Wednesday.

“The Secretary-General calls in the strongest terms for an immediate end to the fighting, de-escalation, and stricter observance of the 2020 ceasefire and principles of international humanitarian law,” Guterres’ spokesman Stephane Dujarric said.