Each country said the other had promptly violated a humanitarian truce that took effect at midnight on Sunday, as fighting continues over the long-disputed Nagorno-Karabakh region.
The conflict over the disputed territory that broke away more than two decades ago appears to rage on despite the truce brokered by Moscow over the weekend.
Azerbaijan's second-largest city was targeted by missiles on Sunday, government officials say. Armenia denied the charges. The clash is part of a decades-long dispute over territory.
The Kremlin has close relations with Armenia and Azerbaijan. Turkey supports Azerbaijan. "The Turkish factor in this war is obvious and looks extremely threatening," says a Russian political analyst.
Dozens of service members on both sides reportedly have been killed in violence that began Sunday in the disputed Nagorno-Karabakh region. The conflict has the potential to draw in NATO ally Turkey.
Each country is blaming the other for initiating the conflict, which has reportedly left civilians dead on both sides. Armenia has declared martial law and mobilized its military.
