(CBS News) BEIRUT - Fierce fighting is being reported in Syria's two biggest cities. The street battles have left parts of Damascus and Aleppo in ruins, and forced thousands more civilians to flee the violence.
Until a few days ago, Syria's two main cities had been bubbles of relative stability, but heavy fighting is now driving a flood of refugees over Syria's borders, with thousands fleeing to Turkey or Lebanon.
They're seeking safety from a civil war that has finally come to their doorsteps.
"In my home (in the Damascus suburbs), I could see the helicopters bombing and tanks firing," one refugee told CBS News.
In the capital, Syrian soldiers have regained control of neighborhoods that had fallen at least in part to opposition fighters. State television told viewers government troops were mopping up remnants of people dubbed "terrorists" by the regime.
But as the fighting dies down in one area, it flares up in another.
Aleppo has seen fierce clashes over the past 48 hours. The city - Syria's second largest and most important economically - had been a center of support for the president, but that is now clearly fraying.
As for President Bashar Assad, he appeared for the second time on television since a bombing that killed four of his top officials, but there was no confirmation on where exactly he is or to what extent he's in charge.
As the opposition offensive continued, the Free Syrian Army claimed Sunday it had seized yet another border post on Syria's frontier with Turkey.
This has been the bloodiest week since fighting began: 1,260 have been killed, including 299 government forces.