Syrian security forces have killed a local al-Qaeda leader and scores of foreign-sponsored insurgents during heavy clashes near the eastern city of Deir al-Zour, Press TV reports.The Syrian army carried out a mop-up operation on the outskirts of the city, situated about 420 kilometers (262 miles) northeast of the capital Damascus on Sunday and engaged a group of armed men. Ammar Nawar al-Hajr, an al-Qaeda leader and insurgent commander, was shot dead along with a number of his comrades in the battle. Meanwhile, Syrian forces repulsed insurgent attacks on army checkpoints in the suburbs of Damascus. Several insurgents were killed and many more injured in the exchange of fire between gunmen and the Syrian army. Syria has been experiencing unrest since March 2011. The Syrian government says that the chaos is being orchestrated from outside the country, and there are reports that a very large number of the insurgents are foreign nationals.