The Turkish Foreign Ministry says in a press release that the move was part of a pilot project prepared by a working group formed under the Astana process by Turkey, Russia, Iran and the United Nations.
Syrian regime and opposition groups have swapped detainees in northern Syria, the Turkish Foreign Ministry said on Saturday, describing it as a first step to build confidence between the warring sides.
The move was part of a pilot project prepared by a working group formed under the Astana process by Turkey, Russia, Iran and the United Nations to investigate the fate of missing people and release those who have been detained, the ministry said.
Press Release Regarding the Mutual Release of Detainees in Syria as part of the Astana Process https://t.co/KjOnh6AnIx— Turkish MFA (@MFATurkey) November 24, 2018
It did not specify how many people were involved in the swap but the Syrian Observatory for Human Rights, a UK-based war monitoring group, said rebel factions had released 10 hostages in return for the regime releasing 10 detainees.
"Some people who were held in detention in Syria by rebel groups and the regime were set free in the area, under rebel control, of Abu Zindeyn south of Al Bab," said a written statement from the Turkish ministry.
"The aim is to maintain with new initiatives this practice, which represents an important first step in terms of building confidence between the sides," it added.
The Syrian regime's news agency SANA said nine men and one woman "were liberated" after militants held them in the Aleppo countryside.
A video on SANA showed them on a bus clapping and cheering.
Civilian casualties in Idlib
Syrian regime shelling killed seven civilians including five children on Saturday in a planned buffer zone around the country's last major rebel bastion, the Syrian Observatory for Human Rights said.
A teacher and four schoolchildren were among the victims after the shelling hit near a school in the northwestern province of Idlib, the group said.
Regime ally Russia and opposition backer Turkey in September agreed to set up a demilitarised cordon around the region of Idlib to stave off a massive regime offensive.
But the deal's implementation has stalled after rebels refused to withdraw from the expected buffer zone by a mid-October deadline, and sporadic shelling and clashes have since rocked the area.
The teacher and four children were leaving the school in the town of Jarjanaz in the southeast of Idlib province when the artillery fire hit, said Observatory chief Rami Abdel Rahman.
Saturday's killings are the latest in a string of similar incidents, according to the Britain-based monitor, which says it relies on sources inside Syria for its information.
Meanwhile, at least 47 US-backed militants have been killed in counter-attacks by Daesh in eastern Syria over the past two days, the war monitor said.
The Syrian Observatory for Human Rights raised the death toll from an earlier figure of 24 after it said Daesh militants launched three fresh assaults on Saturday.