BEIRUT - Rebel forces took control of a strategic town in northern Syria on Monday, cutting off government forces' only supply route out of the city of Aleppo, the Syrian Observatory for Human Rights said.
The Britain-based monitoring group also said it had obtained a photograph showing the execution of Alawite cleric Badr Ghazal by hardline Islamist rebels, highlighting the growing sectarian bloodshed of the 2-1/2-year conflict.
The Observatory, which opposes President Bashar Al-Assad's rule, said rebels took control of Khanasir, a town that sits on the government supply route connecting Aleppo with the central city of Hama.
The rebel gain will leave government forces besieged in Aleppo province, the Observatory said.
Further south, residents in the central province of Homs said rebels also tried on Monday to retake the strategic town of Talkalakh, 4 km (2.5 miles) from Lebanon's northern border. Its capture would allow rebels in the Homs countryside to replenish their supplies.
For weeks, Assad's forces had been on the offensive in Homs, a province they consider vital to securing their hold from Damascus to the president's coastal stronghold. The coast is home to a large number of Assad's Alawite minority sect, an offshoot of Shi'ite Islam, who mostly support the president.
But the advance near Talkalakh and the purported assassination of an Alawite cleric suggest the rebels are tentatively trying to push back in central Syria.
Sectarian violence has increasingly overtaken a conflict that began as peaceful protests against four decades of Assad family rule but has now become an all-out civil war.
Syria's Sunni Muslim majority has largely supported the uprising and hardline Islamist groups among the rebels have increasingly threatened Alawites in retaliation for the killing of Sunnis.
The sectarian dimension of the conflict has drawn in foreign fighters from neighbouring countries. Lebanese Shi'ite militant group Hezbollah has sent men to fight alongside Assad's forces, angering Sunni Muslims in Lebanon and the region.
Some Syrians were sceptical about the purported killing of the Alawite cleric Ghazal, saying there was still no definitive proof. It was not immediately possibly to independently verify the report because of the restrictions imposed on foreign media.
Either way, the alleged killing or capture of Ghazal in Latakia province is a symbolic threat to Alawites on the coast, whose heavily fortified region has largely been spared the violence raging in most of the country.
The Observatory said rebels from the Nusra Front shot Ghazal after he was kidnapped by rebels in the northern suburbs of Latakia earlier this month. It was not clear when the execution had occurred.