More than 18,000 people have been flown out of Kabul since the Taliban took over Afghanistan's capital, a NATO official said on Friday, pledging to redouble evacuation efforts as criticism of the West's handling of the crisis mounted. The speed with which the Taliban conquered Afghanistan as the U.S. and other foreign troops completed their withdrawal surprised even their own leaders and left power vacuums in many places. Media in Britain reported its spy chiefs might face a grilling over intelligence failings. The governments of Germany and Australia have also faced calls to do more and speed up the evacuation of citizens and vulnerable Afghans. On Thursday, G7 foreign ministers called for a united international response to prevent the crisis from worsening, in comments echoed by countries including Russia.