Wouldn't be so sure about that. The Syrian government has no problem using helicopter gunships, nobody is stopping them from using fast jets. This is from today in Hama:
Could be routine, could be nothing. I haven't seen any evidence so far of the Air Force being used besides for recon but I imagine it wont be long before you start to see Assad getting really desperate and ordering his pilots to drop bombs on towns. That jet's landing at the same airport where the helicopter's that are rocketing towns are based. I wouldn't put it past that guy.
To be honest, I'm not sure anymore since I can't find a pic of anything that resembles a Syrian MT-LB.
EDIT:
Actually, in the end it does seem to be a BMP-1 seeing where the exhaust smoke is coming from.