President Bashar al-Assad has begun moving chemical weapons to airports in case of "external aggression", according to the Free Syrian Army (FSA).
"Assad has transferred some of these weapons and equipment for mixing chemical components to airports on the border," the FSA said just one day after the regime was warned not to consider using chemical weapons by the US.
The FSA also claim that Assad's regime began moving weapons several months ago "with the goal of putting pressure on the region and the international community."
Should the FSA reports be correct, the move will increase tensions with America and the international community.
On Monday, Syria's government spokesperson Jihad Makdissi said that "any stocks of chemical weapons that may exist, will never, ever be used against the Syrian people," and would only be considered in the case of "external aggression."
The same day, US President Barack Obama assured that Assad's regime "will be held accountable by the international community and the United States should they make the tragic mistake of using those weapons," while the UN secretary general Ban Ki-Moon labelled the idea as "reprehensible", and the Foreign Secretary William Hague
According to Sky News, the moving of any weapons will alarm nearby Israel, who fear any weapons could be passed on to the Lebanese group, Hezbollah.
Meanwhile, violence flared in the Syrian city of Aleppo, with clashes between rebels and forces loyal to Assad moving into a fourth day.
The Britain-based Syria Observatory reported heavy fighting after midnight in several neighbourhoods as well as shelling by regime forces.