Azerbaijan handed over 15 captured Armenian soldiers in exchange for land mine maps, the two countries' foreign ministries said on July 3.
Azerbaijan and ethnic Armenian forces fought a six-week war that ended with a Moscow-brokered cease-fire in November which saw Baku regain control over parts of the disputed Nagorno-Karabakh region and seven adjacent districts.
In a statement, Azerbaijan’s Foreign Ministry said Russia mediated a deal for Armenia to provide maps detailing the location of around 92,000 anti-tank and anti-personnel mines in the recaptured Fizuli and Zangilan regions.
"As a humane step, the Azerbaijani side has extradited to Armenia 15 people of Armenian origin," it said.
Once the soldiers arrived home, Armenia provided their names and said they were all from the Shirak region in the northwest of the country.
"As a goodwill gesture, the Armenian side provided Azerbaijan with maps of minefields in the Fizuli and Zangilan regions," the Armenian government said.
Nagorno-Karabakh and surrounding districts are among the most heavily mined areas of the former Soviet Union.
Since the November cease-fire, seven Azerbaijani troops and 18 civilians have died and more than 100 have been wounded by land mines in the area.
Azerbaijan’s government hopes obtaining mine maps will help save lives and accelerate construction so that people displaced from villages and towns during a bloody conflict in the early 1990s can return to their lands.
In June, Azerbaijan and Armenian struck a similar deal that traded 15 prisoners for mine maps of the Agdam district.
The number of Armenian prisoners of war and other detainees still in Azerbaijani custody is unclear.
The cease-fire agreement provided for the exchange of prisoners of war and other detained people, leading to an exchange of 44 Armenian and 12 Azerbaijani prisoners in December.
But since the cease-fire, Azerbaijan has captured as many as 60 Armenian servicemen amid lingering border disputes and mutual recriminations.
Part of the difficulty in resolving the issue is that Azerbaijan doesn't consider all the detainees prisoners of war -- a distinction that would give them protections under the Geneva Conventions -- but merely captives because they were detained after the cease-fire.