Azerbaijan on Saturday released to Armenia 15 prisoners of war captured last year during hostilities over the disputed Nagorno-Karabakh region, the foreign ministry in Baku said.
The ministry also said that under the deal mediated by Georgian Prime Minister Irakli Garibashvili, Yerevan reciprocated by providing Baku with maps of minefields in the conflict zone.
Fighting broke out between Azerbaijan and Armenia in September 2020 over Nagorno-Karabakh, claiming around 6,000 lives over six weeks.
The war ended in November with a Russian-brokered ceasefire under which Yerevan ceded swathes of territory it had controlled for decades.
On Saturday, "Azerbaijan handed over to Armenia 15 detained Armenians in exchange for the map of 97,000 anti-tank and anti-personnel mines in the Agdam district," one of the territories Armenia has ceded to Baku, Azerbaijan's foreign ministry said in a statement.
The ministry also thanked US Secretary of State Antony Blinken, top US diplomat for Europe Philip Reeker, European Council President Charles Michel, and the OSCE Swedish chairmanship for their roles in the negotiations.
"Our brothers returned to their families thanks to the efforts of Georgia's Prime Minister Irakli Garibashvili, our Georgian brothers as well as our partners from the US and EU," Armenian Prime Minister Nikol Pashinyan told journalists.
He said he had earlier "provided Azerbaijan with a certain number of minefield maps through Russian Foreign Minister Sergei Lavrov."
Garibashvili's office said in a statement: "An important step has been made towards the amelioration of the security environment in the South Caucasus region."
- 'First step' -
A senior EU diplomat said Michel helped broker "parallel humanitarian gestures" prior to the agreement's announcement.
Michel considered it "a first step towards renewing confidence, an effort the EU is ready to fully support", the diplomat added.
Russia, which has deployed peacekeeping troops to Karabakh, also welcomed the move.
"Wonderful and long-awaited news. We welcome such steps," foreign ministry spokeswoman Maria Zakharova said on Telegram.
The mountainous region of Nagorno-Karabakh is one of the most heavily mined places in the former Soviet Union.
Seven Azerbaijani troops and 18 civilians have died and 110 have been wounded by mines in and near Nagorno-Karabakh since the ceasefire, the Azerbaijani government says.
Both Azerbaijani and Armenian forces planted mines during a bloody conflict in the early 1990s.
Tensions have been again running high since May, when Armenia accused Azerbaijan's military of crossing its southern border to "lay siege" to a lake shared by the two countries.
Pashinyan at the time asked Russian President Vladimir Putin for military support.
Moscow said it would help with the delimitation and demarcation of the neighbours' borders.
Aliyev said last month that Azerbaijan was ready for peace talks with Armenia, while Pashinyan announced later the two ex-Soviet nations were holding discussions on the delimitation and demarcation of their shared borders.
Ethnic Armenian separatists in Nagorno-Karabakh broke away from Azerbaijan as the Soviet Union collapsed, and the ensuing conflict has claimed around 30,000 lives.