Syrian army is ready to use chemical Sarin bombs from bomber aircraft against the rebels 0612121.

Sarin is classified as a weapon of mass destruction by the United Nations, and its production and stockpiling is outlawed under the 1993 Chemical Weapons Convention.

U.S. President Barack Obama, Secretary of State Hillary Clinton and other world leaders have warned Assad the use of chemical weapons is a red line that would bring strong consequences.

Syrian forces earlier Wednesday pressed a counteroffensive against rebels near Damascus as a report indicated the regime army was weakening against rebel gains.

Western officials and military analysts told The Washington Post the Syrian army was showing serious cracks as emboldened rebels notched new victories and regime forces retrenched.

Opposition troop successes stem, in part, from funding and weapons from wealthy Arab Persian Gulf donors and Syrian businessmen outside the country, the Post said.

They also reflect the degraded state of the Syrian army, which appears low on supplies and morale, analysts told the newspaper.

Troops loyal to Assad and rebel forces clashed in several southern Damascus suburbs where rebels have scored several tactical victories in recent days, the Syrian Observatory for Human Rights said.

They also fought as opposition troops advanced toward Damascus International Airport, the British-based Observatory said.

Rebels and regime forces also clashed around the strategically important Wadi al-Deif military base near the northwestern city of Maarat al-Numaan that earlier saw Syrian jet fighters bombing attacking rebels, activists said.

The fighting came a day after a mortar attack on an elementary school 10 miles north of Damascus killed at least 15 people and perhaps 30.