Bilal al-Sudani is alleged to have been a key figure in the funding and expansion of the Islamist militant group across Africa and beyond.

Officials say he was killed during a gunfight after troops raided a remote mountainous cave complex in northern Somalia, hoping to capture him.

In a statement the US Secretary of Defense Lloyd Austin said no civilians were harmed in what he described as "a successful counterterrorism operation.”

Analysts say the fact that troops were sent to kill or capture Mr Sudani, rather than using a less risky drone strike, indicates his significance.