GYUMRI, Armenia -- Dozens of protesters demanded Moscow apologize and that commanders at Russia's military base in Armenia be held responsible after a soldier was arrested on suspicion of murdering six members of a family at their home near the installation.
As authorities discussed which country will prosecute the soldier, officials took pains to prevent the killings from sparking large-scale tension between Russia and Armenia, its only ally in the South Caucasus.
Russian officials said Private Valery Permyakov was detained by the Russian Federal Security Service's border guards in Armenia on January 13, shortly after midnight, while trying to cross the border into Turkey dressed in civilian clothing.
He was handed over to the commander of the Russian base in Gyumri, Armenia's second-largest city.
The deputy chief of Armenia's police force, Unan Pogosian, told reporters in Gyumri that Permyakov confessed to the January 12 attack, in which a couple, their son, and daughter-in-law, a 2-year-old granddaughter, and an unmarried daughter were shot dead.
The couple's 6-month-old grandson was stabbed but survived.
Officials have not commented publicly on a possible motive or said whether Permyakov knew the victims.
Pogosian said Russian and Armenian authorities were discussing which country will have custody of Permyakov and lead the investigation and prosecution.
It appeared likely that Russia would do so. The Armenian Prosecutor-General’s Office said that, according to the Russian Constitution, Russian citizens detained by Russian authorities on suspicion of committing crimes cannot be handed to another country's custody.
In Gyumri, Armenian Defense Minister Seiran Ohanian told journalists that "the incident must not be politicized and used to worsen Armenian-Russian ties."
The senior lawmaker in President Serzh Sarkisian's party, Vaghram Bagdasarian, told RFE/RL that the tragedy must not be used to spark debate about the presence of the Russian base.
But dozens of activists protested outside the Russian Embassy in Yerevan, demanding that Permyakov's commanders be held responsible.
Protesters said that since the suspect is a Russian soldier, he represents Russia and Russia must formally ask forgiveness from the Armenian nation.
Bagdasarian, speaking to RFE/RL in Yerevan, said that the attack will be investigated thoroughly and anyone found responsible will be brought to justice.
He said he believes "control over the base must be intensified so that we are more vigilant."
"It is not by chance that today a Russian commission arrived in Gyumri and our defense minister is there as well," Baghdasarian said, adding that "they are discussing the issue so that similar events would never take place in future."
Russia has about 3,000 troops at the base in Gyumri, one of its largest military installations abroad and a key foothold in the South Caucasus, which is nestled between Russia, Iran, Turkey, and the energy-rich Caspian Sea basin and is a focus of geopolitcal rivalry.
Armenia is a member of the Collective Security Treaty Organization (CSTO) and the Eurasian Economic Union, two groups of former Soviet republics that the Kremlin uses as instruments of power in the region.