The Islamic State (Isis) has allegedly kidnapped about 150 Assyrian Christians after seizing the key town of Qaryatain, in the central Homs province, from forces loyal to president Bashar al-Assad. Sources from A Demand for Action (ADFA), an organisation campaigning for Christian minorities in the country, said that 300 families managed to flee from the area but some 142-150 people were abducted by the extremist group.

"People have tried to reach their relatives on their mobile phones with no luck," said a statement from the advocacy group. "The Islamic State has said that they have 'arrested' more than 100 Assyrian/Syriacs from the town of Qaryatain in Homs, Syria."

The kidnapping was confirmed by the UK-based Syrian Observatory for Human Rights which reported that 230 civilians from the town, including "dozens of Christians, 45 women, 19 children and 11 families", were abducted by IS.

Observatory chief Rami Abdel Rahman told AFP that those abducted were wanted by the extremist group for "collaborating with the regime", and that included at least 60 Christians.

Their names were on a list used by the jihadists as they raided the town. Those who tried to flee were quickly tracked down and abducted.

Some of Assyrians were taken from the Syriac Catholic Mar Elian monastery, where priest Jacques Mourad was abducted in May. Mourad was known to help both Christians and Muslims and was preparing aid for the arrival of hundreds of refugees from Palmyra.

The jihadist group captured Qaryatain, which lies south-west of Palmyra Roman ruins and 85km from Homs, after heavy clashes with regime forces. The Assyrians, also known as Chaldeans, are an ancient ethnic group belonging to the Syriac Christianity and speaking Aramaic.

Earlier in February, IS kidnapped hundreds of Assyrians after a three-day assault on a chain of 10 Syrian villages in the north- eastern province of al-Hasakah. According to the latest figures, at least 222 people are still missing.

UPDATE: Nuri Kino, founder of ADFA, told IBTimes UK that the definitive number of Syriac Orthodox and Syriac Catholics kidnapped by IS is 250. The figure comes from local churches' records.

He added that 1,500 people who had fled Qaryatain just arrived in Homs, where the Syrian Orthodox Archdiocese has launched a desperate appeal for water, food and medecins.

Kino said he spoke with two refugees who have family members missing and they were screaming "When will these atrocities against us stop?".

"We are obviously asking Isis to release these innocent people, but we're losing hope given what happened before in Syria," Kino said. "Around 222 people are kidnapped and we don't know anything about their whereabouts."

Amnesty International's Syria researcher Neil Sammonds said:

"The abhorrent abduction in Syria of more than 200 people by Islamic State highlights the dreadful plight of civilians caught up in the conflict in the country.

"The group must respect the rules of war and immediately release these civilians unharmed.

"Every effort must be made to identify the perpetrators of these crimes and bring them to justice."