"U.S. citizens are strongly encouraged to maintain a high level of vigilance," the agency said on its website.
The FBI said Ayman al-Zawahri and Osama bin Laden coordinated the 9/11 attacks.
New details continue to emerge from authorities about the 18-year-old suspected of killing 10 people at a Buffalo supermarket. Here's what's known so far about the suspect, Payton Gendron.
Authorities said evidence shows a mass shooting at a Buffalo supermarket was a hate crime. The Department of Justice is calling it, "an act of racially-motivate violent extremism."
Frank R. James, 62, the suspect in the shooting of 10 people aboard an N train in Sunset Park, Brooklyn was ordered held without bail Thursday during his arraignment in Brooklyn federal court. He could spend the rest of his life in prison if found guilty of throwing smoke grenades and opening fire on a crowded train.
Mohammad Ahmad al-Qahtani was flown back to Saudi Arabia, to a treatment facility.
Boston Marathon bomber Dzhokhar Tsarnaev's $1,400 COVID-19 stimulus payment can be used to help pay the millions of dollars he is ordered to pay his victims, a judge has ruled.
Saturday's attack marked the first known time that a suicide bomber has killed victims in eastern Congo, where an Islamic State group affiliate earlier this year took responsibility for a suicide bombing near another bar in Beni who had caused no other casualties.
Jeffrey Rambo, an agent who acknowledged running checks on journalists in 2017, told federal investigators the practice is routine.
While DHS said it had no credible information on a specific threat, the agency warns in its latest national terrorism advisory bulletin that mass gatherings for the upcoming religious holidays could be potential targets.
A senior al-Qaida leader was killed Friday in a U.S. airstrike, officials said.
ISIS says its members are responsible for a deadly suicide bombing on a Shiite mosque in southern Afghanistan.
The Supreme Court sounds ready to reinstate the death penalty for convicted Boston Marathon bomber Dzhokhar Tsarnaev.
Twenty years ago, the 11th of September dawned as just a date. By midnight, it was 9/11, the staggering starting point for a new era of terror, war, politics, patriotism and tragedy.
France began the trial of 20 men accused in the Islamic State group’s 2015 attacks in Paris that left 130 people dead and hundreds injured.
The U.S. continued with evacuations in Kabul on Friday with tighter security measures amid warnings of more possible attacks.
U.S. Marine Corps Lance Corporal Kareem Mae'Lee Grant Nikoui was one of the 13 U.S. servicemembers killed in action while stationed at the Hamid Karzai International Airport in Kabul, Afghanistan on Thursday.
Three families have made it out of Afghanistan after they went to the country to visit relatives and got stuck there amid the recent chaos.
Afghanistan's ISIS-K refers to the 'Khorasan' branch of Islamic State.
A Proud Boys leader who was taken into custody days before the Jan. 6 riot was sentenced to five months behind bars on Monday for burning a D.C. church’s Black Lives Matter banner, and also for weapons charge.