The Syrian Observatory for Human Rights is reporting heavy fighting in Deir Ezzor Syria, where a group of soldiers were sent to look for pro-government fighters who went missing in the desert. They came upon ISIS fighters and got into a substantial battle.
The incident was in western Deir Ezzor, in the desert area. This desert has a lot of remote areas where ISIS remnants were believed to be located. The remnants are seldom active because nothing is out there, but patrols are opportunities for ambush.
The patrol went out and the government lost contact with them, so they sent “tens of military vehicles” in to look for them. Unsurprisingly, they found their way into a fight, though casualties are so far not being reported.
ISIS has been accused of trying to reconstitute in eastern Syria, though largely this has not happened, with the group having lost its meaningful territory a long time ago.