The United States says it will not be intimidated after an attack on a UN guest house and a hotel in Kabul.Five United Nations foreign staff were killed in one of Tuesday’s attacks. Washington says it was an attempt to disrupt Afghanistan’s November 7th presidential run-off election, but it will not succeed. The UN Secretary General Ban Ki-Moon also sharply criticized the attack. He said, “I condemn this shocking and shameless act and the terrorists who committed this crime. It is unjustifiable by any standard.” The UN says it will review security measures following the killings. The world organization has operated in Afghanistan for more than 50 years. Hours after the Kabul attacks US Secretary of State Hillary Clinton arrived in neighbouring Pakistan. She said defeating the Taliban and stabilizing Afghanistan is a key plank in America’s regional strategy against the militants. Clinton said, “We commit to stand shoulder to shoulder with the Pakistani people in your right to fight for peace and security. We will give you the help that you need in order to achieve your goal.” Pakistani security forces are also engaged in a bloody conflict with the Taliban. A bomb killed 105 people in a crowded market in the north-western Pakistani city Peshawar on Wednesday.