Well known to Kenyan authorities before today’s attack, he is reported to have been a military commander, based in Mogadishu, and is thought to have become the man responsible for leading al-Shabaab’s attacks within Kenya. Last month he was named the person who had sent 12 terrorists to plot an attack against the Kenyan parliament in Nairobi. He is also listed as being subject to asset freezes in Britain.

Shortly before Christmas, Kenyan police circulated images of two terror suspects with a reward offered for any information leading to their arrests. One of them was Mohamud.

Gideon Kimilu, deputy director of the Kenya Police Criminal Investigation Department in Nairobi, said the two are believed to be behind attacks including that on a bus in Mandera on the Somali border when 28 non-Muslims were murdered in November. Ten days later, 36 non-Muslim quarry workers were murdered.

“He commands the militia along the border and is responsible for cross-border incursions in the country,” police said. Mohamud had intensified attacks in northern Kenya and the coastal region before Christmas. He is reported to have three wives.

Police said he became a principal at the Madrasa Najah Islamic School in Garissa between 1997 and 2000 where his “extremist tendencies became more manifest”.

He joined al-Shabaab about 15 years ago. He is believed to have an extensive terror network within Kenya, particularly at the Dadaab refugee camp.