ISTANBUL (Reuters) - Turkish police have detained four Syrians suspected of involvement in organising the passage of a boat which capsized, drowning 12 people including a toddler, as they travelled from Turkey to a Greek island, Dogan news agency said on Thursday. It said that the four, including a boat captain, were held on Wednesday evening and that their questioning was continuing. (Writing by Daren Butler; Editing by Nick Tattersall)