Regime aircraft hammered opposition bastions nationwide on Sunday as rebels said they now control most of the country and have moved their command centre from Turkey to "liberated areas" inside Syria.

At least 40 people were killed, the Syrian Observatory for Human Rights said, as aircrafts carried out strikes in central Homs province, Deir Ezzor in the east and areas of Damascus.

Apartment blocks in Albu Kamal, a town in oil-rich Deir Ezzor province, were targeted as rebels and soldiers battled on the ground in several districts of the town on the Iraqi border.

Al Jazeera's Jamal Elshayyal reports.