The death toll from the attack, which targeted a tea shop near heavily guarded government institutions on Friday evening, was significantly higher than the four previously reported.
"On the evening of July 2, a suicide bomber wearing a vest detonated the device near the Juba Hotel, killing at least 10 people with dozens injured," the ministry of information, culture and tourism said in a statement.
"The attack occurred during a busy hour where the victims were enjoying a local tea shop," it added, saying the "malicious" attack was by Al-Shabaab.
The Al-Qaeda-linked group swiftly claimed responsibility for the attack in a statement saying "15 elements from the governmental intelligence, police, and militia were killed and 22 others were wounded."
Sources told AFP that the attack took place just a few hundreds metres from the headquarters of the Somali Intelligence Agency at around 5:30 pm (1430 GMT) Friday.
"The cafe was crowded when the blast occurred," said witness Abdikarim Ali.
The cafe is often frequented by members of the Somali security forces, sources said.
Al-Shabaab, which is fighting to overthrow the internationally-backed government in Mogadishu, regularly attacks government and civilian targets in Mogadishu.
The group controlled the capital until 2011 when it was pushed out by African Union troops, but still holds territory in the countryside.
