Two Russian military medics succumbed to injuries suffered during militant shelling of a field hospital in the war-torn Syrian city of Aleppo on Monday, Russia's Defence Ministry said.
Another member of the medical staff, a doctor, was also wounded in the mortar attack and was "fighting for his life," Defence Ministry spokesman Igor Konashenkov said in comments carried by the Interfax news agency.
A number of civilians being treated at the medical facility were also injured, Konashenkov said, attributing blame to opposition forces. Russia is a major backer of Syria's embattled ruling regime, a longtime ally.
An independent monitoring group, the Syrian Observatory for Human Rights, said eight civilians were killed in rebel shelling on the city's government-held western sector.
The observatory reported government advances deeper inside the city's rebel-held eastern sector on Monday. Hundreds of civilians throughout the city have been killed in shelling and airstrikes this year.
In the past, Russia and the Syrian President Bashar al-Assad's regime have been repeatedly accused of attacks on medical facilities in Aleppo and other rebel-held areas.
Amnesty International charged in March that for Russia and the Syrian regime "wiping out hospitals appears to have become part of their military strategy."
Rebel-held eastern Aleppo is almost devoid of medical facilities after its remaining underground hospitals were hit in repeated airstrikes. Medical supplies are very scarce due to the siege imposed on the enclave by government forces.
A rescue worker inside eastern Aleppo told dpa on Monday that "most health centres are destroyed and we are left with the minimum."
"People pray now to die at once and not get wounded because they have no one to rush to rescue them and no place to go to for treatment," Ibrahim al-Haj of the White Helmets rescue group said.
The UN Security Council will vote later Monday on a resolution calling for a week-long ceasefire in Aleppo, in order to allow humanitarian aid to be let in.
The observatory said Monday that Syrian regime troops and their allied forces took control the Kadi Askar neighbourhood overnight, and now hold more than two-thirds of eastern Aleppo.
Russia has been pushing for the removal of rebels from eastern Aleppo as Syrian troops seek to take control of the entire city.
Russia plans to conduct talks with the United States later this week about imposing a deadline for rebels to leave the area, Foreign Minister Sergei Lavrov said Monday. "All armed groups that refuse to leave eastern Aleppo will be considered terrorists."
The talks, to begin in Geneva on Tuesday or Wednesday, should establish evacuation routes, Lavrov said in comments carried by Interfax. "As soon as the routes are agreed, a ceasefire regime will enter into force to allow the evacuation."
The US, which has condemned the Syrian regime as perpetrating crimes against humanity, including killing civilians, supports some rebel groups seeking to overthrow the regime.
However, both the US and Russia acknowledge the necessity of ridding Syria of United Nations-designated terrorist organizations, such as Islamic State and al-Qaeda-linked fighters.
Russia has alleged that al-Qaeda-linked militants are largely in control of eastern Aleppo and are holding civilians hostage, although the UN and analysts say the militants are a smaller proportion of the rebel forces in the enclave.
Over the last 10 days, government forces have made key advances in Aleppo's rebel-held east as defences collapse amid a gruelling five-month siege and years of airstrikes and shelling.
By Weedah Hamzah and Peter Spinella
