Armenian protesters stormed the government house in the capital Yerevan on Tuesday, demanding to see the country's leader after he signed a ceasefire deal with Azerbaijan and Russia.
The declaration follows six weeks of heavy fighting in the contested Nagorno-Karabakh region, sparking fears of a wider regional war feared to have killed thousands.
The territory is internationally recognised as part of Azerbaijan but populated and, until recently, fully controlled by ethnic Armenians -- who have been relentlessly pushed back by Azerbaijani forces.
Russian President Vladimir Putin later announced Russian peacekeeping troops would be deployed along the frontline in Nagorno-Karabakh and in a corridor between the region and Armenia.
"Internally displaced persons and refugees are to return to Nagorno-Karabakh and bordering areas under the supervision of the High Commissioner of the United Nations for refugees. There will be an exchange of war prisoners, other detainees and exchange of the dead. All economical and transport contacts to be un-blocked. Transportation will be supervised with help of Russian Border Service."
The deal is likely to be seen as a sign that Russia is still the main arbiter in a region it regards as its own backyard.
Russia has a defence pact with Armenia and a military base there, while Azerbaijan has been backed by staunch ally Turkey.
Under the deal, Azerbaijan will get to keep all of its territorial gains, and ethnic Armenian forces must hand over control of a slew of other territories between now and December 1.
Azerbaijan said Monday it had seized dozens more settlements in Nagorno-Karabakh.
It also claims claims it's retaken much of the land that it lost in a 1991-94 war which killed an estimated 30,000 people and displaced many more.
Armenia, however, has denied the extent of Azerbaijan's territorial gains.
Three ceasefires have failed in the past six weeks and Azerbaijan's superior weaponry and battlefield gains have reduced its incentive to seek a lasting peace deal.
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