The deadly incident occurred in central part of the capital on Monday, when an explosive-laden car exploded next to an Italian café, across from the Immigration Directorate, on a major thoroughfare.
The huge blast also left 10 people wounded, police added.
“The blast was very powerful and there were a lot of people there at the time, I saw several people dead and injured,” said a witness, Abdukadir Ise.
Other reports said that gunfire erupted after the explosion, which sent thick clouds of smoke to the sky.
No group or individual has claimed responsibility for the attack, but such assaults bear the hallmarks of al-Qaeda-linked al-Shabab Takfiri terrorists.
The blast came a few hours after a roadside bomb blast killed at least three Somali soldiers outside a military base on the outskirts of Shalan Bood town, located in the Lower Shabelle region, south of Mogadishu, while the government troops were on an ordinance-clearing mission.
Al-Shabab Takfiri terrorist group claimed responsibility for the bomb attack, but said the attack had killed four government forces, including two officials.
“We went out of town in search of bombs but one had been planted right on the spot where we were based,” said Mohamed Nur, regional military official, adding that the blast wounded four other troopers.
The deadly incidents came a day after Somalia’s information minister announced that a Friday raid by the army on Bariire village, also located in the Lower Shabelle region, had killed the terror group’s leader Moalin Osman Abdi Badil and three of his associates.
Somalia has been the scene of deadly clashes between government forces and al-Shabab militants since 2006.
The Takfiri militant group was forced out of the capital by African Union troops in 2011 but still controls parts of the countryside and carries out attacks against government, military and civilian targets.
Al-Shabab has stepped up its deadly bombings in the capital since new President Mohamed Abdullahi Mohamed took office in February.
Somalia’s armed forces are under growing pressure to take full responsibility for the security situation in the country as a multinational African Union force prepares to start withdrawing in 2018.
By Africafrique and agencies