The United Nations has come under attack in Afghanistan. Officials there say a roadside bomb ripped through a U.N. vehicle, killing five people. From Islamabad, VOA correspondent Benjamin Sand reports.

U.N. spokesman Aleem Siddique says the blast Tuesday morning was in the southern Afghan province of Kandahar.

"The blast has claimed the lives of an Afghan driver and four Nepalese contractors working with the U.N. Office for Project Services," he said.

The U.N. vehicle was driving down the main road just outside Kandahar city.

The United Nations says the bomb was apparently detonated by remote control and was not a suicide attack.

The southern provinces are the Taleban's traditional stronghold and fighting there has continued unabated since U.S.-led forces ousted the Islamic militants from power in 2001.

Taleban commanders have already claimed responsibility for the explosion. U.N. officials sharply condemned the attack.

"Intentional attacks on civilians are a clear violation of international humanitarian law and the United Nations will be pursuing full accountability for those who are behind this," said Siddique.

The blast was the first deadly attack on the United Nations in nearly 11 months.

Security experts say Taleban attacks on civilians in general have surged dramatically, with more than 700 non-combatants killed in the past 15 months and thousands more seriously injured.

2006 was Afghanistan's deadliest year in more than half a decade and this year shows no signs of any improvement.

The fighting eased during the recent winter months when heavy snows restricted the Taleban's movement. But Afghan officials say attacks are again on the rise and the insurgency appears to be back with a vengeance.

On Monday, a suicide bomber in the northern city of Kunduz killed at least nine policemen and injured more than 25 others.

Officials there say it was the first large attack in the relatively stable northern provinces in several months and the deadliest since 2001.