The Syrian troops have driven out foreign - backed militants from the northwestern city of Aleppo as part of their clearing operations in the country.The advancements came on Saturday as the Syrian government forces completely flushed out militants from the towns of Aziza and Tall Assan, located near Aleppo. The army says it also discovered tunnels dug by the militants in Aziza, and secured a strategic bridge that links several towns in the Aleppo countryside. The Syrian forces regained control over two key areas in Ghouta, near the capital, Damascus, where a large number of militants were killed in the operations. The military also succeeded in securing the al-Mashtal region, which is located near the western city of Homs. The Syria crisis began in March 2011, and many people, including large numbers of soldiers and security personnel, have been killed in the violence. The Syrian government says the chaos is being orchestrated from outside the country, and there are reports that a very large number of the militants are foreign nationals. In addition, several international human rights organizations have accused foreign-sponsored militants of committing war crimes.