Capt. Mohamed Hussein told The Associated Press that an additional 13 people were wounded and most of the casualties were soldiers.
The Somalia-based extremist group al-Shabab claimed responsibility for the blast in Mogadishu, saying it targeted vehicles carrying government officials.
The car bomb exploded at a security checkpoint near the presidential palace as soldiers were conducting security checks on vehicles on the main road. A white column of smoke rose over the seaside city as gunfire rang out and people scattered.
The al-Qaida-linked al-Shabab frequently carries out such blasts in the capital near the presidential compound and at hotels frequented by government officials and foreigners.
"In the past I was wounded in this area, and again today my daughter has been killed in this attack which also destroyed my home. This is terrible," witness Madey Ahmed told the AP.
Amid the crumpled vehicles and tangled metal roofing, a small corps of yellow-vested workers carried bodies and began sweeping the dusty street.
At U.N. headquarters in New York, Somali Ambassador Abukar Dahir Osman paid tribute to Fahiye, saying: "We are more determined to fight the menace of faceless, borderless international terrorism."
He told a U.N. Security Council meeting on Somalia that "al-Shabab continues to be a threat undermining our efforts to deliver security."
"We have made significant gains against al-Shabab in the past eight weeks," retaking two strategic towns in Lower Shabelle, Osman said. But he said the extremist group enjoys "a comparative advantage" because the government is still under a U.N. arms embargo.
Associated Press video journalist Mohamed Sheikh Nor and AP writer Edith M. Lederer at the United Nations contributed to this report.
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