Syrian government warplanes have pounded a rebel-held neighbourhood in the central city of Homs, killing at least three people and wounding dozens, opposition activists said.

Syria’s civil war is closing in on president Bashar Assad’s seat of power in Damascus with clashes between government forces and rebels flaring around the city today, raising fears the capital will become the next major battlefield in the 20-month-old conflict.

Syria acknowledged for the first time that it had chemical and biological weapons, saying they could be used if the country faced foreign intervention.

Syria has denied UN claims that government forces used heavy weapons during a military operation that has brought widespread international condemnation against president Bashar Assad's regime.

Syria’s foreign ministry has denied government troops were behind an attack on a string of villages that left more than 90 people dead.