A suicide bomber in Afghanistan attacked a Kandahar neighborhood, Monday, housing offices belonging to the United Nations and several U.S. charities. The blast left four dead and the U.N. buildings badly damaged.

The incident comes only two days after an attack on an armored NATO bus in Kabul.
    
Saturday's suicide bombing of the U.S.-led NATO mission killed 17 people in the deadliest attack yet. The French Press Agency reports 10 of those who died were Americans.
    
The Pakistan-based Haqqani Network is suspected of being behind the attacks. The group has ties to both al Qaeda and the Taliban.

The bombings come as the U.S.-led coalition is in the process of transferring security responsibilities to its Afghan counterparts.

Coalition leaders plan to withdraw combat forces by 2014. 

"Despite the insurgency's failures this past year, it remains capable and, enabled by safe havens in Pakistan, continues to contest (Afghan and NATO) progress in some parts of the country," German Brig Gen. Carsten Jacobson, a coalition spokesman in Afghanistan told reporters in Kabul.