Islamic State has released 37 elderly Assyrian Christians who were among about 200 seized by the militants in February in northeastern Syria, two human rights monitoring groups said on Saturday.
Elders from Arab tribes had mediated with the jihadists for their release, the Britain-based Syrian Observatory for Human Rights said.
The Assyrian Human Rights Network said the captives had been returned to the town of Tel Tamer and that they were in good health. It posted a picture showing several people including one woman, who was weeping.
The Assyrian network also said in a statement on Facebook on Saturday that negotiations continue for the release of another 124 who remain in captivity.
The hardline Sunni Muslim militants have now released 88 from the original group, it said in a statement on its Facebook page, and negotiations were continuing to secure the freedom of the remaining 124.
They were captured during battles with the Syrian Kurdish YPG militia when Islamic State fighters overran more than a dozen villages inhabited by the ancient Christian minority near the Syrian city of Hasaka, close to the Iraqi border.
Islamic State fighters killed three of the Assyrians last month, according to the two monitoring groups.