Decades-old tensions erupt again into fighting, prompting fears of a major escalation.
The disputed Nagorno-Karabakh region in the South Caucasus is at the heart of a decades-long armed standoff between neighbours Armenia and Azerbaijan, which has reignited in recent days.
The predominantly forested and mountainous region is recognised under international law as part of Azerbaijan. However, ethnic Armenians who form the majority of the population in Nagorno-Karabakh, reject Azerbaijani rule. It broke away from Azerbaijan in a war in the 1990s but no country recognises the region as an independent republic.
Heavy fighting in Nagorno-Karabakh has prompted fears the dispute could spiral once again into all-out war, as the United Nations called for an immediate ceasefire. See what the armies of Armenia and Azerbaijan have at their disposal, and how much money these two countries are investing in their defence sectors.