“We have confirmed the death of six UN staff, including a foreign national,” police official Abdullahi Mohamed said.
“The bomb is believed to have been attached to the minibus and was detonated near the UN office.”
Witnesses and security officials suggested the explosion could also have been from a roadside bomb that was detonated as the minibus, which is used to transport staff from a guesthouse to the UN compound, was passing.
Garowe, in the northeastern region of Somalia, is capital of the semi-autonomous Puntland region.
There was no immediate claim of responsibility, but Somalia’s Al-Qaeda-affiliated Shabaab insurgents carry out regular attacks, targeting both government officials and foreign aid workers.
“Investigations are still ongoing to establish how it happened but I can confirm you that the UN compound was not affected,” Mohamed added.
The Shabaab rebels are fighting to overthrow Somalia’s internationally-backed government. They have also carried out revenge attacks across the wider region against countries which contribute troops to the African Union force in Somalia, AMISOM.
Shabaab attacks in Somalia have targeted key government and security sites in an apparent bid to discredit claims by the authorities and AU troops that they are winning the war.
On Saturday, Shabaab gunmen shot dead a Puntland lawmaker, Adan Haji Hussein.
On Sunday, the Shabaab killed three AU troops in an ambush in the south of the war-ravaged country.