VIENNA - Austrian authorities have detained a 14-year-old boy who was allegedly planning to travel to Syria and had researched on the internet how to build bombs, prosecutors said on Wednesday.The boy, a Turkish national who has lived in Austria for about eight years, was taken into custody late on Tuesday."He admitted he had plans to go to Syria and searched the internet for plans on how to build explosive devices," said Michaela Obenaus, spokeswoman for prosecutors in St. Poelten, the capital of Lower Austria province. "There is suspicion of participation in a terrorist organization."Obenaus said the boy had expressed sympathy with Islamic State militants fighting in Syria and Iraq.Authorities have to decide within two days whether they will extend his detention by a further two weeks. The age of criminal responsibility starts at 14 in Austria.Authorities are already investigating cases relating to around 150 people who have traveled from Austria to join militant groups fighting in Syria and Iraq.Some have already been killed, while media have speculated for months about the fate of two teenage girls from Bosnian families who reportedly traveled from Vienna to Syria to marry Islamist fighters. The 15- and 17-year-old girls are listed as missing persons on the Interpol website, which also shows one of them wearing a veil with Islamic writing covering her face.Other European countries are also struggling to prevent radicalized youngsters traveling to the Middle East.