Islamic State group
The US assistant attorney general sends a warning to terrorists after two IS "Beatles" are charged.
After being taken hostage by the so-called Islamic State in 2013, no one knows for certain what happened to American aid worker Kayla Mueller.
By Frank Gardner
BBC security correspondent
The BBC and human rights researchers examined a video of a killing in northern Mozambique.
By Secunder Kermani
One of the largest collections of extremist material belonging to the group has been uncovered.
By Shiroma Silva