KABUL - Taliban militants launched a coordinated attack on a UN compound in the center of the Afghan capital, Kabul, on Friday setting off explosions and battling the security forces.A plume of smoke hung over the city center after the attack was launched, eight days after six Americans, soldiers and civilians, and nine Afghans were killed in a suicide car bombing in Kabul.The Taliban, fighting to expel Western forces and establish Islamist rule, claimed responsibility, saying a compound used by the US Central Intelligence Agency (CIA), had been attacked.