The three suspects in the terrorist plot on Taylor Swift concerts in Vienna are to remain in custody for another month, a city court said on Friday. A spokeswoman for the Vienna Regional Court said the trio would be held until at least September 23 due to the risk of collusion and further offences. The 19-year-old main suspect and a 17-year-old accomplice are under investigation for membership of a terrorist organization. The third suspect, aged 18, admitted to being a member of the Islamic State terror group but is not thought to have been involved in the plans to attack concert-goers at the …