Rebels seized an air defense base near Syria's strategic southern international highway on Saturday, March 23, activists said, according to Reuters.

Syria's southern provinces bordering Jordan and Israel have become an increasingly significant battleground as the capital comes into play, with President Bashar al-Assad's forces and his loyalist militias hitting back hard to prevent rebel advances.

The Britain-based Syrian Observatory for Human Rights, which has a network of sources across Syria, said the base commander was among those killed in the two-week battle for the air defense site in Deraa province bordering Jordan.

"Fighters from the Nusra Front, Yarmouk Martyrs Brigade, and other battalions seized control of the 38th division air defense base, near the town of Saida on the Damascus-Amman highway, after 16 days of fierce clashes," the Observatory said.

The Nusra Front is an Islamist militant group suspected of links to al Qaeda and blacklisted by the United States as a "terrorist group". Its forces, which include foreign fighters, have come to increasing prominence in the revolt.

Videos published by opposition activists showed cheering fighters driving tanks around the base and loading boxes of ammunition onto flatbed trucks. The rebels also said in the videos they had freed dozens of prisoners held at the base.

A video uploaded by the Observatory showed what it said was the body of base commander General Mahmoud Darwish lying in a pool of blood in a bathroom.

Other activist videos showed the corpses of soldiers in camouflage fatigues scattered in the grass outside the base, shot in the head.

It was not immediately possible to verify the pictures or opposition reports. The Syrian government has severely restricted access to Syria for foreign journalists and international aid groups.