Kenyans and Somalis were killed in a bomb blast that destroyed a UN vehicle on its way to the UN compound in Garowe, the regional capital of Puntland, early Monday.

A police officer said the bomb had apparently been planted under a seat and was detonated by remote control. But witnesses 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.

"Investigations are still ongoing to establish how it happened, but I can confirm you that the UN compound was not affected," police officer Abdullahi Mohamed told the DPA news agency.

The Islamist al-Shabab militia claimed responsibility for the attack.

Al-Shabab's actions had been focused on southern Somalia, where the group is fighting against the government. Such attacks are unusual in the northern parts of the country.

On Saturday, however, al-Shabab gunmen shot dead the Puntland lawmaker Adan Haji Hussein.

Al-Shabab is 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.

Attacks on key government and security sites are an attempt to discredit claims by the government and AU troops that they are winning the war.

Al-Shabab was also responsible for the attack on the Garissa university in neighboring Kenya last month.

rg/jil (AFP, AP, Reuters, dpa)