Over 150 soldiers killed in clashes between Armenia and Azerbaijan

State of play: Armenia's Prime Minister Nikol Pashinyan said Wednesday that 105 Armenian service personnel have been killed in the fighting, Reuters reported.

• Azerbaijan said on Tuesday that 50 of its soldiers had been killed, per AP.
• Azerbaijan's defense ministry claimed in a statement Tuesday that it was responding to "large-scale provocations" by the Armenian military, including the shelling of its military positions and infrastructure.

What they're saying: Russia's Foreign Ministry called on Armenia and Azerbaijan "to refrain from further escalation of the situation, exercise restraint" in a statement Tuesday.

• "We are in close contact with Baku and Yerevan. An appeal was received from the Armenian leadership with a request to assist in resolving the situation in accordance with the existing bilateral agreements and through the [Collective Security Treaty Organization]," a Moscow-led security military alliance of which Armenia is a member.

The big picture: The fighting overnight was the worst escalation of hostilities between the two countries since the end of the 2020 war in Nagorno-Karabakh, the New York Times reports.

• Azerbaijan made significant gains in and around the region during the six-week war that killed more than 6,000 people.
• The Russia-brokered peace deal that ended the war sparked protests in Armenia's capital, Yerevan.
• As part of the deal, Russia agreed to send peacekeepers to the region for five years, though its ability to fulfill the commitment has come into question with its invasion of Ukraine.

Go deeper: CIA chief says Russia will pay "a heavy price" for war on Ukraine

Editor's note: This article has been updated with new details throughout.