Turkish PM says unclear if suicide bomber linked to any group

ANKARA (Reuters) - Turkish Prime Minister Ahmet Davutoglu said on Tuesday it was not immediately clear whether a suicide bomber who attacked an Istanbul police station had links to any particular group but that he had ordered "the most comprehensive investigation". "The authorities are investigating whether there is a link to any group ... We have given instructions for the most comprehensive investigations," Davutoglu told reporters in a brief statement in the capital Ankara. (Reporting by Asli Kandemir and Humeyra Pamuk; Writing by Nick Tattersall; Editing by Jonny Hogg/Mark Heinrich)