berlin police bring experts explosives robot investigate suspicious package find christmas market west german city bonn late friday bonn police cordoned evacuate large area market p.m. local time experts still examine object five hours late spokesman say assume dangerous still investigate spokesman say say object discover shortly market close even crowd germany high alert potential attack year fail tunisian asylum seeker anis amri kill 12 people hijack truck drive crowd berlin christmas market chancellor angela merkel mark first anniversary attack tuesday say germany learn security shortcomings expose incident german authorities evacuate part christmas market potsdam near berlin early month package contain powerful firecrackers wire nail deliver nearby pharmacy officials late say criminals use incident try extort millions euros logistics firm dhl deliver package police evacuate bonn christmas market probe suspicious package