Reported Syrian gas attack killing hundreds after first US-trained rebel incursion from Jordan

Syrian opposition activists report between 200 and 650 dead and hundreds more wounded in a poison gas strike by Bashar Assad’s forces on rebel-held areas of eastern Damascus. They claim nerve gas canisters were dropped by Syrian Air Force fighter planes which were seen flying over the area after the attack, the most extensive reported till now. Their claim has not been verified. The regime denied the accusation, saying there was “no truth whatsoever” in reports that chemical gas was used near Damascus, and maintaining over state television that the Syrian army was conducting a conventional attack on rebel positions south and east of Damascus.
DEBKAfile reports exclusively that Assad is acting to counter the first organized incursion of US-trained Syrian rebels from Jordan into southern Syria. The first group of 250 rebels, trained in special operations tactics by US and Jordanian instructors, entered Syria Saturday, Aug. 17, armed with weapons of Russian provenance supplied by the US and Saudi Arabia.
They are fighting under US and Jordanian commanders based in the Hashemite Kingdom.
A second group of 300 fighters crossed into Syria from Jordan Monday.

They are linking up with local rebel groups chosen from amongst those with no ties with the jihadist Jabhat al-Nusra (Al Qaeda in Syria).
According to our military sources, the rebel units are advancing at speed along the Syrian-Israeli border. They have forced the Syrian brigades posted there into retreating from positions inside a strip of 1-25 kilometers from the border, and captured the villages of Raihaniya, Breiqa and Beer Ajam.
This tactic has moved the Syrian army back from the area opposite the Israeli Golan, and started marking out a buffer zone between Israeli and Syrian forces in the Horan province.
DEBKA’s military sources report that additional Syrian rebel forces are standing ready in Jordan to cross into Syria. The incoming forces will then start extending the nascent buffer zone northward towards Deraa (fountainhead of the Syrian uprising in 2011) and east toward Jabal Druze.

This Jordan-based rebel offensive was launched shortly after Gen. Martin Dempsey, Chairman of the Joint US Chiefs of Staff, visited US forces in Jordan and inaugurated the underground US war room near Amman for commanding the operation in Syria.
Syrian ruler Bashar Assad has more than once declared that if the Syrian capital Damascus came under threat, he would resort to chemical warfare and the entire Middle East including Israel would go up in flames. For now, his army is fighting to keep the rebels from taking control of southern Syria.