Egyptian police have detained the former information minister and state broadcasting chief as part of an anti-corruption probe following the ousting of President Hosni Mubarak.
The move comes a day after three other officials appeared in court on charges of money laundering and abuse of power.
Meanwhile, Egypt's new cabinet met for the first time, amid criticism that key Mubarak-era figures were not replaced.
Opposition groups plan to rally on Friday to call for a new cabinet.
They also want an end to the emergency law and for political prisoners to be freed.
Last Friday, millions of Egyptians returned to Tahrir Square to celebrate the victory of their revolution, which led to the resignation of Mr Mubarak on 11 February after 18 days of street protests.
They have vowed to keep up the pressure until their demands are met.
On Thursday, ex-information minister Anas al-Fikki and former state radio and television chief Osama al-Sheikh were arrested as part of a probe into alleged graft.
Mr Fikki is the fourth member of Mubarak's former government to be detained, after the former ministers of interior Habib al-Adly, tourism Zuhair Garana, and housing Ahmed al-Maghrabi.
On Wednesday, Mr Garana and Mr Maghrabi - along with steel tycoon and prominent ruling NDP party leader Ahmed Ezz - appeared in Cairo Criminal Court to face corruption charges.
The men wore white prison uniforms and sat in a metal cage. An angry crowd of hundreds taunted them as they arrived in court, screaming "thieves" and "you robbed our money", the AFP news agency reported.
Atef Obeid, Egypt's prime minister from 1999-2004, and former culture minister Farouk Hosni have been banned from leaving the country pending further inquiries, along with several businessmen close to Mr Mubarak's regime.
Egypt's top prosecutor earlier requested the freezing of the foreign assets of Hosni Mubarak himself, as well as his wife, his two sons and two daughters-in-law.
All the officials say they are innocent.
The crackdown comes as Egypt's new cabinet set to work, with security high on the agenda.
The 10-member cabinet was sworn in by Field Marshal Mohamed Hussein Tantawi, head of Egypt's military supreme council which is running the country until presidential and parliamentary elections later this year.
Despite the inclusion of opposition figures for the first time, the key portfolios of defence, interior, foreign affairs, and justice were unchanged - sparking objections from the opposition Muslim Brotherhood and other groups.
In the run-up to elections, a committee is also working to amend the constitution in line with the protesters' demands. Their work is expected to take about a month, an army source said.
The revolutions in Tunisia and Egypt have prompted a wave of popular uprisings across the Middle East and North Africa, with Libya's Col Muammar Gaddafi fighting off the biggest challenge to his rule in over four decades.