Violence has been escalating as the Islamic State of Iraq and Syria moves through the country ravaged by a three-year civil war. On Thursday, ISIS seized Syria's largest oil field from another al-Qaida affiliated terrorist group that has embedded itself among the opposition.
"We took it [the oil field] over without any fighting," said one commander in a YouTube video. "They fled like rats."
Oil production in the country has dropped from 400,000 barrels per day to 25,000 since the beginning of the war.
ISIS has even started to take control of areas held by other radical groups. The town Sheheil, a Nusra front stronghold, released a statement declaring loyalty to ISIS.
"We have decided to declare our allegiance to the Islamic State and the Caliph of the Muslims, Abu Bakr al-Baghdadi," one activist said.
Another video was released showing the village of Ishara saying that they would cease their resistance to ISIS.
"The clans of the city of Ishara, and the villages around it ... and all of the factions in these areas ... announce before God that they will cease fighting with the Islamic State," said a man surrounded by tribal elders.
ISIS's advancements are not only alarming in Syria, but also Iraq where they have gained control of key cities as they inch closer to the capital of Baghdad.
ISIS has declared authority over all Muslims and plans to create one large Islamic caliphate.