Boukamal, the last major IS stronghold in Syria, was taken by government soldiers and their allies on Thursday. IS militants withdrew from the town and launched a counteroffensive over the past two days.
Rami Abdurrahman of the Britain-based Syrian Observatory for Human Rights and Omar Abu Laila, a Europe-based opposition activist originally from Syria's eastern province, said Saturday that IS fighters are now once again in full control of the town.
There was no government comment.
Syrian state TV on Friday aired live footage from inside the town after activists said IS fighters retook parts of Boukamal.
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