Egyptian security forces stormed the offices of Al-Jazeera Egypt on Thursday, confining its journalists to one room and confiscating equipment, the channel's bureau chief told AFP.
Ahmed Zain said the officers entered the channel's new premises, roughed up staff, forced them into one room and took away their identity papers.
One of the reporters, Hayat al-Yamani, asked for the security officers' identity papers but they refused and pushed her to the ground.
Police at the nearby Agouza station later refused to take her statement, Zain said.
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Equipment including cameras and a laptop were also confiscated, he said.
It was the second such raid on Al-Jazeera Egypt this month.
On September 11, the channel said authorities prevented it from broadcasting after raiding its offices and confiscating transmission equipment, on the basis that it lacked official licensing.
Zain said that on March 20 Al-Jazeera Egypt had requested official authorisation, and that it had been assured it could continue broadcasting in the interim.
The ruling authorities have cracked down on media outlets seen as diffusing information likely to cause instability in Egypt during its transition following the February ouster of president Hosni Mubarak and transfer of power to the army.