Islamist militant group al-Shabab has said it was behind the attack on a hotel in the Somali capital, the BBC reported Friday.
The al-Qaeda linked group has been driven out of the country's major towns but still controls many rural areas in the south.
An al-Shabab spokesman said they had killed the officials while they were praying because they are "apostates".
It has previously said it would target members of the government.
Earlier this month, al-Shabab shot dead an MP in a drive-by shooting in Mogadishu.