Arabi-Press report also said the al-Nusra Front systematically threatens the families of FSA officers.
Fearing the influence of al-Nusra Front, most FSA officers do not have the courage to speak out about numerous treasons committed by the al-Qaeda offshoot against the ongoing revolt in Syria.
The treacherous acts include attempts to assassinate FSA officers and striking political and military deal with different parties including the ruling government in Syria.
A Syrian opposition figure said the al-Nusra Front is headquartered in the towering white building of an eye hospital in the volatile city of Aleppo. Between 300 and 500 militants are reportedly stationed in the headquarters.
The unnamed militant said the Syrian Army’s artillery is deployed only one kilometer away from the al-Nusra headquarters where Dushka-mounted vehicles are parked or moving.
He noted that the Syrian Army has never opened fire on the al-Nusra headquarters.
Syria has been gripped by turmoil since March 2011 and the foreign-sponsored militancy has taken its toll on the lives of many people, including large numbers of Syrian soldiers and security personnel.
Damascus says the West and its regional allies, such as Qatar, Saudi Arabia, and Turkey, are supporting the militants.
In an interview broadcast on Turkish television in April, Syrian President Bashar al-Assad said if the militants take power in Syria, they could destabilize the entire Middle East region for decades.
In addition, several international human rights organizations say the militants operating in Syria have committed war crimes.
The al-Qaeda-linked al-Nusra Front has assassinated a large number of the so-called Free Syrian Army (FSA) officers, a report says.