The blog entry, which is anonymous but appears to be written by a female sympathiser in Tanzania, says that Lewthwaite is known in terror circles as "Dada Mzungu", which means "white sister" in Swahili.

"More than five times our 'Dada Mzungu' has defeated the kuffar [non-Muslims] in Kenya and Tanzania," she writes. "She gave her life to Allah and she now serves Allah as His female soldier. In +252 [Somalia] she commands her 'all-female mujahid terror squad' and conducts her operations against the kuffar.

"Now every Muslim sister wants to be like our 'Dada Mzungu'. I will join you." The blog entry adds: "She came to Kenya to torment the kuffar and left the kuffar in a state of "confused" [sic] as we say. The kuffar hunt her but still can't find her, for Allah protects His warriors."

Kenyan police sources in Mombasa confirmed that according to their intelligence, Lewthwaite was in southern Somalia, where she is being protected by al-Shabaab, the militant Islamist army.

"We cannot say that she is connected to any terrorist attacks in Kenya, but it is consistent with our information that she is with Shabaab in Somalia," one senior anti-terror officer in Mombasa said.