The exact number of people being held was unknown, but Fr. Emanuel Youkhana, who heads the Christian Aid Program Northern Iraq, CAPNI, said that more than 100 residents had been captured during the assault, which began in the pre-dawn hours of Feb. 23.
"Knowing the brutal barbaric record of IS with the captured, the destiny of those families is a major concern to us," Youkhana said in a Feb. 24 e-mail.
The priest said at least two villages — Tal Shamiran and Tal Hermiz — remained surrounded by Islamic State forces overnight.
It was not immediately clear what the militants would do with the abductees.
The Catholic charity Aid to the Church in Need reported that thousands of people fled the villages nestled along the Khabur River and were able to reach the largely Kurdish-controlled city of Hassakeh, Syria, to the east.
Bishop Aprim Nathniel of the Assyrian Church of the East reported that a local church and community hall were overloaded with people who fled the villages.
Syriac Catholic Patriarch Ignace Joseph III Younan said he had been unable to reach Bishop Jacques Hindo in Hassakeh.
"We pray and hope that these latest tragic events end without killing and abusing our Christian community," the patriarch told Catholic News Service Feb. 24 from the patriarchate in Beirut.
"It is shameful that the whole world, beginning with the so-called Western nations, became accustomed to these aberrations of religious and ethnic cleansing, in the name of a volatile, unrealistic Western democracy that never existed in countries ruled by Muslims. This is why the eradicating fanaticism is spreading in the latter nations," said Patriarch Younan, who was born in Hassakeh.
He said the Islamic State raids on the Assyrian villages were in an area fueled by confessional hatred.
"So it is quite possible that they attacked innocent, defenseless Christians, where no Syrian army exists, but only civilian defenders, in order to revenge serious losses suffered up north, near Qamishli," he said.
Nuri Kino, head of A Demand for Action, which works to protect religious minorities in the Middle East, told the Associated Press that the militants took between 70 and 100 Assyrians, including women and children.
The Britain-based Syrian Observatory for Human Rights, with a network of activists in Syria, also reported the abductions and said that about 90 Christians were being held by Islamic State forces, the Associated Press reported.
As the assault unfolded, Youkhana said, Arab Sunni villagers from a nearby Assyrian village rescued 15 Assyrians who were expected to make their way to Hassakeh.
Kurdish forces managed to join the fight to slow the Islamic State advance, various media reported.
The Associated Press also reported that the Islamic State group's online radio station, Albayan, said in a report Feb. 24 that Islamic State fighters had detained "tens of crusaders" and seized 10 villages around Tal Tamr after clashes with Kurdish militiamen. Islamic State militants frequently refer to Christians as "crusaders."
Assyrians are an ethnic group whose origins are in ancient Mesopotamia. They are a Christian people; the Chaldean Catholic Church was formed by a group of Assyrians who broke away and joined the Catholic Church in the 16th century. The Assyrians have traditionally lived in what is now Iraq, northeastern Syria, northwestern Iran and southeastern Turkey.