The fighting on the line of contact in Nagorno-Karabakh began on 27 September, with Armenia and Azerbaijan accusing each other of unleashing hostilities. Armenia has declared martial law and - for the first time - general mobilisation, while partial mobilisation has been introduced in Azerbaijan.
The international community has strongly condemned the escalation and called on parties to settle their differences via dialogue, while Turkey has pledged its full support for Azerbaijan.
Yerevan and Baku have signed three ceasefire agreements since the initial escalation in September, but all of them were broken soon after entering into force.
The Nagorno-Karabakh conflict first flared up in the late 1980s, with the predominantly Armenian-populated autonomous region proclaiming independence from Azerbaijan in 1991. As a result, Baku and Yerevan waged a full-scale war for the area between 1992 and 1994 that claimed the lives of around 40,000 troops and civilians from both sides.
A ceasefire was signed in 1994, and the conflict remained frozen, while the self-proclaimed Nagorno-Karabakh Republic (also known as the Republic of Artsakh) remains an unrecognised state.
Follow Sputnik's feed to find out more.
