Egypt's interim premier Hazem El-Beblawy promised to follow up on prosecution investigations in order to release those arrested in protests on Tuesday.
Hours earlier, the Interior Ministry said 52 were arrested following clashes between demonstrators protesting against military trials for civilians in the draft constitution, and security forces who were implementing the recently enacted protest law criminalising unauthorised demonstrations.
Members of the National Salvation Front (an umbrella group of political forces) called for the release of the detainees during a meeting with El-Beblawy, who vowed to follow up on investigations to fulfil their demands.
The statement rules out earlier speculation that the detainees would be released immediately.
The head of the 50-member committee amending the constitution, Amr Moussa, contacted Interior Minister Mohamed Ibrahim, calling for the release of the detained protesters.