Four attackers also died in the assault which was claimed by al-Shabab, Somalia's militant rebels who are allied to al-Qaida.
State Minister for the Prime Minister's Office, Buri Hamza, was among those killed, said Capt Mohamed Hussein, a senior Somali police officer.
Hamza died when his hotel room collapsed Saturday because of the powerful car bomb which extremists used to blast their way into the Nasa-Hablod Hotel.
At least 34 people were injured, according to police and hospital sources.
The attacks have raised concerns about the security of hotels in the seaside capital which has seen numerous attacks by al-Shabab in recent years.
"The trend and lethality of such attacks suggest how vulnerable the security of hotels and the city in general are now," said Mohamed Sheikh Abdi, a Somali political analyst.
"By carrying out such attacks, al-Shabab aims to portray itself as the stronger and dominant force when it comes to the security of the city," he said. "Many residents now shun going to hotels that provide some of the few sources of entertainment available in Mogadishu."
