Al-Qaeda’s Syrian affiliate, the al-Nusra Front, along with the Islamist group Ahrar al-Sham al-Islamiya, were involved in the offensive.
An ISIS- linked YouTube channel published a video showing ISIS militants taking over a cannabis field and setting fire to some of the plants.
The State Department is investigating reports that a second American was killed fighting for the extremists.
According to the United Nations, ISIS trains child soldiers in camps in Aleppo Province, where it's advancing on the ground.
Two aircraft types - a Cold War veteran and a drone - have been charged with hunting down ISIS in Syria after President Obama authorized surveillance flights.
"As a mother, I ask your justice to be merciful and not punish my son for matters he has no control over," Shirley Sotloff said.
U.S. intelligence and anti-terrorism finance experts say the Islamic State could be raising more than $2 million a day.
Duncan Hunter, R-Calif., says North Korea, Iran and Pakistan are more worrisome existential threats to the U.S. than ISIS is.
While the United States has previously accused Bashar Assad of using banned chemical weapons, this is the first time the U.N. has done so.
Syria's three-year long civil war, which began after a failed uprising against Assad in 2011, has claimed hundreds of thousands of lives.
Since the beginning of August, UNICEF has dispatched 33 shipments, totaling nearly 1,000 tons of emergency aid, most of it to Iraq.
Tabqa was the army's last foothold in an area otherwise controlled by the militants, who have seized large areas of Syria and Iraq.
Signs of a homegrown jihadi fighter are not always as obvious as expected.
Douglas McAuthur McCain was an aspiring rapper who apparently turned to Islamic extremism and fought alongside ISIS.
The end of a decade of war brings a large drop in workers at America's biggest defense companies. But the cuts may be over soon.
Kurdish Peshmerga forces will now have weapons from Iran, as well as the U.S., Germany, France and Italy.
The wealthy country has mediated the release of foreign and Syrian captives on several occasions during Syria's 3-year-old civil war.
Tuesday's attack follows a suicide-bomb explosion in a Shiite mosque Monday, which killed 12 people and injured 26 others.
The engineers worked at a thermal plant construction site in the country's south, close to its border with Iraq and Syria.
The move could put the U.S. in the awkward position of an unspoken alliance with dictator Bashar Assad.
The administration has not decided whether to bomb ISIS in Syria, but has approved ramping up surveillance just in case.
Syria's "moderate opposition" fears abandonment, while the Assad regime would be glad to join the "war on terror."