Sept. 30 (Bloomberg) -- The United Nations expressed ``outrage'' over a deadly suicide bombing yesterday in the Afghan capital, Kabul.

``We don't at this stage know the final numbers for dead and wounded but it is clear this attack is among the worst that Kabul has seen,'' Secretary-General Ban Ki-moon's Special Representative Tom Koenigs said in a statement on the UN Web site.

The attack by a suicide bomber wearing an army uniform on an Afghan military bus yesterday killed 30 people and wounded about 30 others, Agency France-Presse reported today.

The attack was aimed at ``terrorizing the population,'' Koenigs said.

The Taliban-led insurgency has stepped up its guerrilla war aimed at the government of President Hamid Karzai and foreign troops.

``Those responsible are evidently incapable of offering anything beyond savagery and murder,'' Koenigs said in a statement. ``They must be made to know they will not prevail.''

The Taliban, ousted from power in 2001, stepped up its insurgency in Afghanistan's southern and eastern provinces last year in response to military operations led by NATO's International Security Assistance Force.

The U.S. has about 10,000 soldiers carrying out anti- terrorism operations in Afghanistan, including hunting for Osama bin Laden. Another 15,000 are under the command of NATO, which is trying to stabilize the country and rebuild infrastructure destroyed by more than 25 years of conflict and civil war.

To contact the reporters on this story: Gemma Daley in Canberra at gdaley@bloomberg.net

Last Updated: September 29, 2007 22:16 EDT