Egyptian police Wednesday fired tear gas at student supporters of ousted president Mohammed Morsi as they protested near the defense ministry against the new military-installed authorities, state media reported.
The protests by students from Cairo University came as a Muslim Brotherhood-led Islamist alliance backing Morsi called for nationwide strike action.
The Brotherhood, to which Morsi belongs, was designated a "terrorist" group last week by the authorities, which accused it of a bombing north of the capital that killed 15 people.
The Islamist movement denied the accusation.
Egypt's state-run Al-Ahram newspaper's website reported that police used tear gas to disperse the protesting students and arrested some of them.
Police also fired tear gas at a pro-Morsi student protest in the Nile Delta city of Zagazig, the deposed leader's home town, security officials said.
Pro-Morsi students have staged defiant demonstrations at universities across Egypt, and earlier Wednesday the pro-Morsi Anti-Coup Alliance called for more protests.
"As the students' strikes succeed in shaking the corners of the coup regime, the coalition of parties, movements and groups defending democracy in Egypt calls for a gradual, decisive nationwide strike," it said.
Police, meanwhile, seized an underground press in the Mediterranean city of Alexandria for allegedly printing leaflets against the security forces, security officials said. Two people were arrested.
The Brotherhood's designation as a "terrorist" group carries harsh penalties.
It could mean death sentences for convicted Brotherhood leaders and five years' imprisonment for participants in protests.
Promoting the group either in writing or verbally can also lead to prison sentences.