Qasr El-Nil police station released on Monday 31 post-graduate degree holders following their arrest on Sunday afternoon at a protest in Cairo's Tahrir Square.
Investigations made by the police determined that those arrested were not participating in the protests, according to a security source.
Tens of masters and PHD graduates initially organised a protest to call for government employment in front of the Egyptian cabinet building in Kasr Al-Nil Street in downtown Cairo.
However, after failing to receive any response from officials, they decided to move to nearby Tahrir Square.
The security forces gave them one hour to end the protest, threatening to disperse it by force if they did not.
Unemployed holders of post-graduate degrees have organised several protests in recent months demanding government jobs.