Egyptian security forces in Cairo arrested on Monday former minister of youth and Muslim Brotherhood leading member Osama Yassin, who faces multiple charges of murder and inciting violence.
Mohamed Hafez, secretary of the Brotherhood's former deputy supreme guide Khairat El-Shater was also arrested.
The two men were reportedly captured in a villa in Cairo's eastern outskirts.
The prosecutor-general had ordered on 31 July the arrest of several Brotherhood figures, including Yassin, who served as Egypt's minister of youth from June 2012 to July 2013.
A dozen Brotherhood leaders and hundreds of members, as well as leading Islamist figures, were arrested over the past week, mainly on charges of inciting violence. The mass arrests come in the wake of the police dispersal of two protest camps in Cairo that supported ousted Brotherhood-affiliated president Mohamed Morsi.
On Sunday, the first hearing of Mohamed Badie, supreme guide of the Brotherhood until his arrest, and of his two deputies, Khairat El-Shater and Rashad Bayoumi, was deferred to 29 October because the defendants could not attend for security reasons.
They are accused of inciting the murder of protesters who died outside the Brotherhood's Cairo headquarters on the evening of 30 June, as angry groups had stormed and ransacked the building.
The Brotherhood have been staging demonstrations and sit-ins in protest of what they describe as a "coup" against former president Morsi, since he was deposed by the army on 3 July as a result of mass nationwide protests against him.