Al-Shabaab spokesman Ali Mohamud Rage said in a statement that the group had targeted intelligence officials who were meeting at the Jazira hotel at the time.
“The apostates are the eyes and the ears of the invaders and these attacks serve as a well-deserved punishment for their role in guiding and assisting the invading forces in their crusade,” he said.
Al-Shabaab said it had killed more than a dozen people in the attack on Wednesday. A medical official has said that at least 11 bodies have been recovered.
Mombasa grenade attack
Meanwhile, in the Kenyan coastal city of Mombasa, a grenade attack on Thursday wounded at least 10 people.
The incident took place at 3.30am at a nightclub that is popular with tourists.
Speaking at the scene, Jack Ekakuro, Kwale area police chief, said: “The club was busy with New Year revellers. Three people appeared from the other side of the road and threw a grenade at the night club which (the grenade) exploded injuring 10 people. The attackers escaped on a motor bike.”
No responsibility for the attack has been claimed, but in the past Kenyan officials have often pointed the finger of blame at al-Shabaab which is currently fighting against African peacekeeping forces for control of territory in the centre and south of Somalia.