The head of the Islamic State in Iraq and Syria has been killed in Iraq in an operation by members of the Iraqi national intelligence service along with U.S.-led coalition forces, the Iraqi prime minister announced Friday.

The killing comes as the group has been reconstituting in Syria, carrying out more attacks than at any time since it lost control of its territory nearly six years ago.

Iraq's prime minister has described Abu Khadija as "one of the most dangerous terrorists in Iraq and the world". On Thursday, an airstrike targeted his vehicle and US forces said they had confirmed his death using DNA tests.