Azerbaijani forces tightened their grip on the breakaway region of Nagorno-Karabakh as international concern mounted over the plight of tens of thousands of ethnic Armenian civilians trapped there.

As the first Red Cross aid convoy crossed into the disputed enclave since Azerbaijan launched a lightning offensive last week, Baku’s forces said rebel “demilitarisation” had begun.

Ethnic Armenian separatist fighters have started surrendering weapons under a Russian-mediated agreement.

On Saturday, the Azerbaijani troops were keen to show off a captured rebel arsenal. They displayed sniper rifles, hundreds of assault weapons, rocket-propelled grenades, and four tanks.

“We have more like that in the forest, but we can’t bring them all here,” said Lieutenant-General Mais Barkhudarov, commander of Azerbaijan’s 2nd Army Corps.

From the Shusha district, outside the regional capital Stepanakert, Azerbaijani Colonel Anar Eyvazov said his soldiers were working closely with Russian peacekeepers to conduct the demilitarisation process.

Azerbaijan now controls the Lachin Corridor to the southwest, which once connected the breakaway region to Armenia. Baku has mounted a de facto blockade there for the past nine months.