Activists fear an all-out assault on Homs, with Syria's embattled regime building up troops around the flashpoint city and activating a security alert in Damascus after surprise protests.
The reported buildup comes as the top US military officer, general Martin Dempsey, warned any intervention in Syria would be "very difficult" and that it was "premature" to arm the unrest-swept country's opposition movement.
Activists and Syrian state media reported that at least 14 people were killed on Sunday, adding to the more than 6,000 people who have died in the Syrian government's 11-month crackdown on dissent. A Homs-based activist voiced fears of an imminent attack on Baba Amr, the main rebel stronghold in the central city, speaking of "unprecedented military reinforcements coming from Damascus."
US drones over Syria
US has deployed a large number of drones over Syria to monitor Syrian military attack on the opposition forces and civilians, NBC News has reported.
Quoting Pentagon officials, the TV channel said that the operation of unmanned aircraft was not a harbinger of a US military intervention in the Syria but to gather evidence that can be used to "make the case for a widespread international response."