The men have been on remand for 11 days; they are accused of breach of the peace for their alleged part in the recent riots in Central and the nearby Hauptbahnhof main train station, Tages-Anzeiger newspaper reported.
The alleged rioters are under investigation for supposedly joining a mob that carried out acts of violence during the riots.
Public prosecutors said the men were being kept locked up to prevent them from communicating with witnesses.
But the father of one of the alleged rioters told the newspaper he believed this was an excuse.
“I suspect they arrested the wrong people, and are now acting as tough as possible to show that something is being done.”
The boy’s father said he is “fairly certain” after talking with his son’s friends that his 18-year old did not directly take part in the riots.
Stephan Bernard, a lawyer for one of the detainees, criticised public prosecutors for not properly explaining why it was necessary to detain the suspects for so long.
But federal prosecutor Daniel Kloiber said he rejected any accusations from lawyers that the treatment was excessive.
“Breach of the peace is not a triviality.” he told the Tages-Anzeiger.
“The maximum sentence is three years, the same as for assault. In addition, several prisoners are strongly suspected of violence and threatening police officers as well as causing massive damage to property.”
Kloiber also dismissed any suggestion that the detentions were politically motivated, pointing out that six custodial judges had checked and approved each remand application.