Azerbaijan said it has handed over 15 Armenian prisoners of war in exchange for a map showing the location of land mines in part of the disputed Nagorno-Karabakh region.
Armenia's acting prime minister, Nikol Pashninan, meanwhile, was quoted by Russian news agencies as confirming the swap on June 12.
The announcement by Azerbaijan's Foreign Ministry said the maps turned over by Armenian authorities detailed the location of nearly 100,000 land mines in the Aghdam region of Nagorno-Karabakh.
"The 15 Armenian captives were turned over on the Azerbaijani-Georgian border with the participation of Georgian representatives," the ministry said.
Speaking during a visit to an eastern Armenian region, Pashinian confirmed the swap.
"I have good news. Fifteen of our captured brothers are returning home. They are on their way now. When they are in Armenia, I will make a more detailed statement," he was quoted by Russia's TASS news agency as saying.
Azerbaijani forces seized swaths of territory in and around the mountainous region during a short war with ethnic Armenia
A Russian-brokered cease-fire ended six weeks of fighting and saw Russian peacekeepers deployed to some parts of the area.
The number of Armenian prisoners of war and other detainees still in Azerbaijani custody remains unclear.
In March, the European Court of Human Rights, where relatives of detainees have appealed for help, referred to 249 Armenians that had been allegedly captured by Azerbaijan and were still detention.
Part of the difficulty in resolving the issue is that Azerbaijani authorities considers some of the detainees not prisoners of war -- with protections under the Geneva Conventions -- but merely captives.
Armenian authorities earlier said that 69 POWs and other detainees had been turned over by Azerbaijan.