Thousands in cars and on foot congregated at a main square in Damascus waving and chanting "Freedom," witnesses said.
Iran believes that Iraq is in danger - this means that Iran is worried militias it backs in Iraq could lose influence.
Iranian Foreign Minister Abbas Araghchi claimed the United States and Israel were behind the latest unrest in Syria.
The pace of events has stunned Arab capitals, Western officials say, raising their fears of a fresh wave of regional instability.
Abu Mohammad al-Jolani, the rebel leader of Hayat Tahrir Al-Sham (HTS), told CNN rebels responsible for abusing dissidents had already been dealt with.
MIDDLE ISRAEL: The civil war’s victors wasted all six years in which they could have rebuilt the land they had destroyed.
A weakened Syrian regime under Assad, therefore, is in Israel’s interest. But here’s the rub: Israel would like to see Assad weakened, but not overmuch, and not toppled.
The rebels captured the cities of Hama and Aleppo within a week and even released prisoners from Hama's central prison.
Russian and Syrian warplanes bombed the area near the border with Turkey on Thursday to try to push back an insurgent offensive that has captured territory for the first time in years.
Videos from Syria shows the group Hayat Tahrir al-Sham inside a Syrian regime base of the 46th Regiment.