A senior member of the blacklisted Muslim Brotherhood (MB) group was arrested in Ain Shams district, eastern Cairo.
Sami Ismael, 48, the head of the MB division in Ain Shams, is wanted for inciting violence and breaking the protest law.
A firearm, a shotgun and ten petrol bombs were found at his residence.
Also, two brothers of the terrorist group were arrested in Ain Shams with a shotgun and a 9mm pistol in their possession.
They were referred to the prosecutor for further probe.