Special to WorldTribune.com

NICOSIA — U.S.-trained Sunni rebels were said to be advancing in Syria.

Opposition sources said Sunni rebels based in Jordan and trained by the CIA were moving through southern Syria. They said the rebels were trying to establish a corridor between the southern Syrian city of Dera and the Golan Heights along the frontier with Israel.

“The rebels have been expanding their hold over Dera despite strenuous efforts by the Syrian Army,” an opposition source said.

The sources said the rebel campaign began in late September 2014 in both Dera and the Golan Heights. They said the rebels, led by Al Qaida’s Nusra Front for the Defense of Levant, forced the Syrian Army and National Defense Forces from positions west and north of Dera.

The regime of Syrian President Bashar Assad has not acknowledged the rebel gains.

So far, the sources said, the Syrian Army remains in control over most of Dera. The rebels, however, have maintained positions west of the city toward the Golan Heights.

The Syrian Army was said to have been stretched thin by multiple fronts around Damascus. The sources said the army and Assad militias were focused on protecting the southeastern approaches of Damascus while the air force intensified strikes on Dera.

“The regime lost Quneitra and its countryside weeks ago, and today it is losing its most fortified positions in Dera,” Syrian Army [Ret.] Hafez Nabil, close to the opposition, told the London-based Al Monitor website.

“These areas are supposed to be fortified the most as they are the closest to the Israeli border. Yet, the regime is now focusing its defenses of the capital, particularly since it is mobilizing for the upcoming battle in Duma in Eastern Ghouta, where the biggest battle will take place.”

The sources said the establishment of a corridor from Dera to the Golan Heights would bring the entire southern Syria under rebel corridor. They said the corridor would also facilitate the flow of weapons and fighters to Damascus.

The Assad regime has acknowledged rebel control over the Golan Heights. Officials said the rebels, led by Nusra, captured positions of the United Nations Disengagement Observer Force, deployed on the Golan since 1974.

“They succeeded in occupying all of the Syrian side [of the Golan],” Syrian ambassador Bashar Jaafari told a briefing on Oct. 14. “The terrorists are now using United Nations cars, which hold the emblem of the United Nations forces in the Golan. They are using the uniform of the UNDOF, the weapons of UNDOF, the positions of UNDOR to shell on the Syrian Army as well as on the civilians in villages.”

But Israeli Defense Minister Moshe Ya’alon also cited the role of the U.S.-backed Free Syrian Army, which was training in Jordan. Ya’alon said Nusra was working with FSA to control the Syrian border with Israel. Many of the Nusra fighters were said to have left the Golan to join Islamic State of Iraq and Levant.

“We’re trying to share our knowledge and experience because we live close by,” Ya’alon said.