ISIS has prompted the U.K. to raise its terror threat alert to the second highest level - "severe."
Authorities say an attack by the terror group is "highly likely."
Now, a report from Foreign Policy is shedding new light on what the terror group may be planning.
Reporters at the magazine say they have gained access to a laptop from an ISIS hideout in Syria. They are calling it "The Laptop of Doom."
More than 35,000 files were found on the computer and include specific instructions on how to develop biological weapons and weaponize the bubonic plague from infected animals. ISIS's advice: "Use small grenades with the virus, and throw them in closed areas like metros, soccer stadiums, or entertainment centers."
OutFront, Foreign Policy Contributor Jenan Moussa.
CNN is learning new details about another American who died fighting for the terror group ISIS.
A friend tells CNN that Abdrackman Mohammed is the second U.S. citizen killed in the fighting last weekend, along with Douglas McAuthur McCain.
A U.S. official says they are trying to confirm his identity.
Like McCain, Mohammed had ties to Minnesota.
CNN is also learning about McCain's childhood friend who was also killed fighting for extremists overseas.
Troy Kastigar is seen in a video trying to recruit others from Minnesota to join the terror group al Shabaab.
"If you guys only knew how much fun we have over here, this is the real Disneyland. You need to come here and join us and take pleasure in this fun. We walk amongst the lions. We sleep under the moon and the stars, they're our lamp. And the wind rocks us to sleep. He places so much tranquility and happiness in your heart when you're amongst these people here. And uh, we can't thank Allah enough."
The mother of Troy Kastigar talks to CNN's Jason Carroll about what may have led her son to join a terror group.
A top Ukrainian army officer said a "full-scale invasion" of his country was under way Thursday, as a U.S. official said up to 1,000 Russian troops had crossed Ukraine's southern border to fight alongside pro-Russian rebels.
NATO released satellite images which it says show Russian self-propelled artillery units moving inside Ukrainian territory.
— OutFrontCNN (@OutFrontCNN) August 28, 2014
And new video shows what the Ukrainian government says is a Russian tank farther south, where a new front is opening up in the conflict.
OutFront, Senator Ben Nelson, who just returned from a fact-finding mission to Ukraine.
Evil. Merciless. Barbaric. Those are just a few of the words that have been used to describe the terror group ISIS, or the “Islamic State.” In the eyes of the United States and its Western allies, ISIS is the new face of international terrorism.
The Obama administration called the brutal execution of American journalist James Foley by ISIS militants a “terrorist attack” and promised to capture his killers.
What is the U.S.’s strategy to defeat ISIS? CNN’s Jim Sciutto hosted a Facebook chat on Wednesday to address your questions on the issue.
CNN has learned a second American may have been killed while fighting for ISIS. According to a coalition of opposition groups in Syria, the second American died in the same shootout where Douglas McAuthur McCain was killed this past weekend.
McCain's relatives, meanwhile, say they are still in shock over the 33-year-old's death.
The question - why are Americans leaving for jihad?
Some 100 other Americans are believed to have either fought in Syria since 2011 or been arrested before they could get there.
So what could cause someone to turn against their own country, leave their family and friends behind to become a jihadist on the battlefield?
OutFront, Ed Husain – was a teenage Muslim growing up in England when he became radicalized in the early 1990's. He is now the senior fellow at the council on foreign relations