Some 12 members of the banned Muslim Brotherhood group have been arrested while holding a secret organizational meeting in Cairo's Zahraa el-Maadi district, the official MENA news agency reported.
A security source was quoted as saying that 12 members of the group were arrested and remanded in custody pending investigation.
Public Prosecutor deputies were present during the search operation and a warrant was issued to search the houses of the arrested members in eight governorates.
Cash, technical equipment and hand-written minutes of the meetings were also seized, according to the source.
Earlier, the banned group told a foreign media that its leader Rashad Bayyumi and some other members were arrested by the police on Friday.
Bayyumi sits on the Brotherhood's 13-member Guidance Bureau. He was arrested at his home in a Cairo suburb, said media reports.
The Muslim Brotherhood, founded in 1928, was officially banned in 1954 but has been usually tolerated.
Presenting its candidates as independents, the Muslim Brotherhood won a record number of seats in parliamentary elections last year, taking 88 of the 454 seats up for grabs in parliament.