World Bulletin/News Desk

Austrian police have detained a 14-year-old boy for the second time on suspicion of belonging to a terrorist organisation, planning to travel to Syria and researching how to build bombs, a police spokesman said on Friday.

The boy from Lower Austria province was first detained in October but released from investigative custody after a few days on condition he remain in contact with authorities.

When his mother reported him missing this week, authorities renewed the arrest warrant.

About 170 people have left Austria to fight in the Middle East, according to the Interior Ministry, some of whom have been killed.

Authorities have said the boy had expressed sympathy with ISIL militants fighting in Syria and Iraq and researched on the internet how to build bombs.

Police picked up the 14-year-old, who authorities have said is a Turkish national, in Vienna on Friday alongside a 12-year-old who will be handed over to his parents as there is no arrest warrant against him, the spokesman said.

Austria last week detained two teenage girls after they tried to travel to Syria to marry ISIL fighters. They have since been released.