Rebels backed by captured tanks have launched a fresh offensive on a government complex housing a police academy near the northern city of Aleppo, prompting the government to respond with airstrikes to try to protect the strategic installation.
If rebels capture the complex on the outskirts of Aleppo, it would mark another setback for President Bashar Assad's regime. In recent weeks, the regime has lost control of key infrastructure in the northeast including a hydroelectric dam, a major oil field and two army bases along the road linking Aleppo with the airport to its east.
Rebels have also been hitting the heart of Damascus with occasional mortars shells or bombings, posing a stiff challenge to Assad's regime in its seat of power.
On Saturday, opposition fighters in the eastern province of Deir el-Zour overran a site known as al-Kibar, which was home to what is believed to have been a partly built nuclear reactor that Israeli warplanes bombed in 2007.
A year after the strike, the UN nuclear watchdog determined that the destroyed building's size and structure fit specifications of a nuclear reactor. Syria never stated the purpose of the site.
After the bombing, the regime carted away all the debris from the destroyed building and equipment from the two standing structures, analysts said, adding that the rebels were unlikely to have found any weapons in the abandoned complex.
"It's more or less a shell because the Syrians decided to remove everything inside the buildings," said Mustafa Alani, an analyst with the Gulf Research Center in Geneva. "I don't think there's anything left really of any value for the rebels."
Rebels have been trying for months to storm the government complex west of Aleppo in the suburb of Khan al-Asal, according to Rami Abdul-Rahman, the director of the Britain-based Syrian Observatory for Human Rights. The facility also includes several smaller army outposts charged with protecting the police academy inside the compound.
Aleppo has been the scene of some of the heaviest fighting of Syria's nearly two-year-old conflict.
In July, rebels launched an offensive on the city, Syria's largest and one-time commercial capital, and quickly seized several neighbourhoods. The battle has since devolved into a bloody stalemate, with heavy street fighting that has left whole districts in ruins and forced thousands to flee.