Syria's rebels announced the launch of a full-scale attack operation, dubbed "the Damascus volcano and earthquakes of Syria," as major clashes engulfed several districts of the capital.

In a statement released on Monday night, the Free Syrian Army's central-Homs Joint Command said its operation was launched at 8:00 pm (1700 GMT), "in response to massacres and barbaric crimes" committed by the regime of President Bashar al-Assad.

The FSA, the statement said, started to conduct "attacks on all security stations and branches in the cities and the countryside, to enter into fierce clashes (with their forces) and to call on them to surrender."

The announcement called for "the encirclement of all security, military and shabiha (pro-regime militia) checkpoints across Syria, and the entry into fierce combat with them in order to eliminate them."

The FSA called for all international roads to be cut off, "from (northern) Aleppo to (southern) Daraa and from (eastern) Deir Ezzor to (coastal) Lattakia, to cut off and seize the supply lines."

It also reiterated calls for defection to the opposition and announced its "work to liberate prisoners and detainees."

The statement said the FSA should consider foreign officers on Syrian soil and allied to the regime—namely Lebanese Shiite militia Hezbollah, the Iranian Revolutionary Guard, Iraqi militias and pro-Assad Palestinian factions—as "legitimate targets."

The statement described "the Damascus volcano and earthquakes of Syria" operation as "the first strategic step towards bringing Syria into a state of complete and total civil disobedience."

In an interview with AFP via Skype, the FSA's Joint Command spokesman Kassem Saadeddine said: "God willing, the statement can be considered an invitation to participate in cutting off the roads to paralyse the movement of regime troops, and to enable the FSA to move freely."