By Mirwais Harooni and Jessica Donati KABUL (Reuters) - A suicide bomber killed dozens of cadets at a Kabul police academy and insurgents struck an area near a U.S. special forces base on Friday in a wave of attacks in the Afghan capital that began with a huge early morning truck bomb explosion. The attacks came just over a week after the Taliban announced a new leader and appeared to dash any hope of a swift return to peace talks between the insurgent movement and the government of President Ashraf Ghani. A Taliban spokesman claimed responsibility for the suicide attack on the police academy, in which security sources said at least 50 or 60 people had been killed or wounded.