The Syrian Observatory for Human Rights said the civilians were taken yesterday in the town of Al-Qaryatain, which IS jihadists had captured late Wednesday.
"Daesh kidnapped at least 230 people, including at least 60 Christians, during a sweep through Al-Qaryatain," Observatory chief Rami Abdel Rahman said, using another name for IS.
Many of the Christians had fled from Aleppo province, in Syria's north, to seek refuge in Al-Qaryatain.
He said those abducted were wanted by IS for "collaborating with the regime," and their names were on a list used by the jihadists as they swept through the town.
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Al-Qaryatain lies at the crossroads between IS territory in the eastern countryside of Homs and areas further west in the Qalamun area.
It had a pre-war population of 18,000, including Sunni Muslims and around 2,000 Syriac Catholics and Orthodox Christians.
According to a Syrian Christian who lives in Damascus but is originally from Al-Qaryatain, the town's Christian population has dropped to only 300.
In May, masked men abducted Syrian priest Jacques Mourad from the Syriac Catholic Mar Elian monastery in Al-Qaryatain, near the IS-captured ancient city of Palmyra.