Discussing the reported military defections in Syria over phone from Norman, Oklahoma, Joshua Landis, director of the Centre for Middle East Studies at the University of Oklahoma, said: "Syria is a deeply divided society. We have to be cautious with this notion of a wholesale mutiny on the part of Sunni soldiers.
"Undoubtedly we have heard of a few, so far individuals.
"Now this tank unit is a new thing. For a whole unit to go over to the other side ... I think that this is something that we will see more of.
"There is a lot of pressure for the army to abandon the regime."