Kenya’s president has removed the country’s interior minister and police chief, hours after Somalia’s Shebab rebels carried out a fresh massacre.

"The military command of al-Shebaab mujahedeen ordered a tactical retreat at midnight," spokesperson Ali Mohamud Rage told AFP.

Al-Qaeda-inspired Shebab rebels in Somalia will accept help from relief groups, lifting the two year ban on foreign aid.

The UN has formally declared parts of Somalia to be in the grip of famine, a move hailed by rebels who now say they will allow aid to be distributed.