An activist group and a local leader say the Islamic State group has released 19 Christians who were among the more than 220 people the militants took captive in northeastern Syria last week.

Bashir Saedi, a senior official in the Assyrian Democratic Organization, says the 16 men and three women arrived safely Sunday and were now at a church in the city of Hassakeh. He says they are all around 50 years of age or older.

The Britain-based Syrian Observatory for Human Rights activist group also reported that 19 Christians had been freed, but put the number at 17 men and two women.

The discrepancy could not be immediately reconciled.

It was not immediately clear why the Islamic State group released them.

The fate of the remaining Christian captives is unclear.