ISTANBUL - Turkey must investigate whether police used excessive force in a crackdown on days of anti-government demonstrations and hold those responsible to account, European Union enlargement commissioner Stefan Fuele said on Friday."Peaceful demonstrations constitute a legitimate way for ... groups to express their views in a democratic society. Excessive use of force by police against these demonstrations has no place in such a democracy," Fuele said in a speech at a conference attended by Turkish Prime Minister Tayyip Erdogan."I am happy that even the government admitted that. What is important now, is not only to launch a swift and transparent investigation but also to bring those responsible to account."