IS kidnapped more than 220 Assyrian Christians in February, after overrunning several farming communities on the southern bank of the Khabur River in Hassakeh province.
Osama Edwards, director of the Assyrian Network for Human Rights, says the women, who are 70 and 75 years old, were released on Tuesday and have now reached the northwestern city of Hassakeh.
The Syrian Observatory for Human Rights said Wednesday the two were likely released because of their poor health. Some of the captives were released previously.
Edwards says the Islamic State is still holding 210 Assyrian Christians and is demanding $100,000 for each hostage.