Hay’at Tahrir Al-Sham’s spokesperson said earlier today that their forces had withdrawn to the southern part of the city; however, some opposition activists have [contradicted] these claims, saying that Khan Sheikhoun is empty.Yes, well, it doesn't look as if there was much to hang around for:
Since losing Talat Al-Nimr in northern Khan Sheikhoun, the militants were under nonstop missile and artillery strikes ...Anyhoo, the SAA right away got busy securing the city, looking for boobytraps, etc.
As to where HTS fell back to, if indeed they high-tailed it from Khan Sheikoun altogether, I'm sure Syrian and Russian reconnaissance pilots told the Syrian Army exactly where they went. Nope, they couldn't tunnel their way out because the SAA found their caves some days earlier.
The SAA, with help from the Russians, has gotten quite good at second-guessing the militants -- and the Turkish government -- have you noticed.