US Secretary of State Hillary Clinton says, some people in Pakistan government are aware of the whereabouts of Al Qaeda leader Osama bin Laden and Afghan Taliban chief Mullah Omar. Clinton told CBS in an interview that these officials may not be at the highest levels. She said, she expected more cooperation to help bring to justice, capture or kill, those who attacked the U.S. on 9/11.Clinton had over the week-end had warned Pakistan that it will face very severe consequences if any terror plot like the failed Times Square bombing was traced to that country.Asked if US was not getting sufficient cooperation from Islamabad in anti-terror drive, the Clinton acknowledged there is a sea change in cooperation by Pakistani authorities, but added that more needs to be done.Her comments came even as other senior US officials including Attorney General Eric Holder said they have obtained new evidence that Pakistani Taliban is behind the attempt to trigger a car bomb blast in the heart of New York.Faisal Shahzad, a 30-year-old naturalised American citizen of Pakistani origin was arrested last Monday for rigging a SUV vehicle to explode in the Times Square.Meanwhile, New York Times has reported that the US military commander in Afghanistan Gen Stanley A McChrystal met Pakistani military chief Gen Ashfaq Parvez Kayani in Islamabad yesterday and pressed for a new military offensive in North Waziristan, the main base of the Pakistan Taliban.