DAMASCUS — (CNN) ISIS fighters overran the strategically important town of al-Qaryatayn in western Syria on Thursday, the London-based Syrian Observatory for Human Rights reported.

The Islamic extremists have abducted more than 200 people, said Rami Abdurrahman, the observatory’s executive director.

Up to 500 people are unaccounted for, but Abdurrahman said the observatory has confirmed that at least 230 people have been taken hostage.

He said that ISIS militants targeted Christians, some of whom were abducted from the town’s Dar Alyan monastery, as well as people believed to have alliances with the Syrian regime.

Towns like al-Qaryatayn are key to ISIS because they are along the Damascus-Homs Highway, a route used to ferry supplies and fighters.

Abdurrahman said he fears that ISIS will also target other Christian population centers in Hawwarin and Sadad.

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