"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.
A Florida man has been sentenced to 20 years in federal prison and 15 years of supervised release for attempting to provide material support to the Islamic State of Iraq and al-Sham, also known as ISIS or ISIL.
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.
FBI officials believe they have not captured all of the people responsible for the Pan Am bombing that killed 270 people, including 190 Americans in 1988.
Jeffrey Rambo, an agent who acknowledged running checks on journalists in 2017, told federal investigators the practice is routine.
The Paris Terror Attacks of 2015 live in the minds of the French every day, but especially on Nov. 13. Here’s a look back at what happened the night of the attacks.
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.
The Taliban have ruled out cooperation with the U.S. to contain extremist groups in Afghanistan.
The Justice Department is preparing to announce charges against two men from Britain who joined the Islamic State and were part of a cell that beheaded Western hostages in Syria.
Police say that several people have been taken to hospital after the Saturday evening attack in the city’s Forbury Gardens Park and that person is in custody.
Police said they have secured the mall, and Public Health Minister Anutin Charnvirakul said there were no more bodies left inside. But he added, "we don't know whether there are any additional injuries or deaths or not." He did not say whether the shooter had been found.
A man stabbed two people on a London street before he was killed by police in what officials describe as a terrorist attack.
Around the world, deadly attacks on houses of worship took place with relentless frequency in 2019.
The White House announced Saturday that Hamza bin Laden, the son of the late al-Qaida leader who had become an increasingly prominent figure in the terrorist organization, was killed in a U.S. counterterrorism operation in the Afghanistan-Pakistan region.