Hundreds of demonstrators have taken to the streets in Christian neighborhoods of Damascus after a Christmas tree burning heightened fears that the overthrow of former President Bashar al-Assad could presage crackdowns on Syria’s religious minorities.

The protests on Monday night appeared to have been sparked after footage, verified by NBC News, showed hooded figures setting fire to the tree at a traffic circle in the Christian-majority town of Al-Suqalabiyah near the city of Hama in central…