Syrian fighters from the Hay'at Tahrir al-Sham (HTS) faction have taken control of Aleppo, where Bashar al-Assad's regime forces abandoned a substantial amount of military equipment, ranging from tanks to aircraft.

Syrian rebels have swept through parts of the country at lightning pace, taking control of the the second-largest city, Aleppo. But who are they and what are their aims?

In a swift and unexpected offensive, Hayat Tahrir al-Sham (HTS) captured Aleppo, Syria’s second-largest city, with minimal resistance from government forces, NPR reports. The Islamist group, formerly linked to al-Qaeda, has transformed into a national entity, focusing on governance and strategic alliances in Syria’s civil war.

One of the oldest cities in recorded history, Aleppo, was seized by the Islamist group Hayat Tahrir al-Sham (HTS) on November 30. Leading the HTS was Abu Mohammed al-Jawlani, a man on who the US has put a $10 million bounty on his head, as well as a man who was given the tag of an apostate by the Islamic State.

Syrian state SANA news agency on Wednesday said insurgents retreated some 20 kilometers (12 miles) from government-held Hama, Syria’s fourth-largest city, as government troops backed by

Syria said Wednesday its counteroffensive has pushed back insurgents attempting to advance to the strategic central city of Hama, while the insurgency says it captured more Syrian troops and Iran-backed militants in fierce battles.

Fox News chief national security correspondent Jennifer Griffin has the details from The Pentagon on 'Varney & Co.'