The spokesperson of the Muslim Brotherhood's Freedom and Justice Party, Yasser Mehrez, has been slammed with a 15-day detention by prosecution on Saturday, reported the Ahram Arabic website.
Mehrez was arrested on Friday on accusations of inciting violence against police and army targets in Cairo and Giza. He was also questioned about recent bombings against police and army targets.
Mehrez denied all accusations.
More than 500 people -- mostly policemen and soldiers -- have been killed in bombings and shootings by militants since July 2013.
Most attacks have been in the restive Sinai Peninsula, but in recent months a number have taken place in the Nile Delta and Cairo.
The authorities blame the Muslim Brotherhood for the attacks and have blacklisted it as a terrorist organisation. The group repeatedly denied involvement in violence.