At least four people have been reported killed in clashes between Egyptian police and Muslim Brotherhood supporters.
The December 27 violence came after the army-backed government this week officially declared the Muslim Brotherhood to be a terrorist organization.
In addition to the four reported fatalities, the Health Ministry said 87 people were wounded in clashes in Cairo and at least four other cities.
The Interior Ministry said 265 people, including women, were detained.
Authorities moved to list the Muslim Brotherhood as a terrorist organization following a suicide bombing December 24 that killed 16 people. The Brotherhood has denied involvement.
Authorities have been carrying out a sometimes bloody crackdown against the Muslim Brotherhood since the military ousted democratically elected President Muhammad Morsi, who had been a leading Brotherhood member, in July.
Based on reports from AP and Reuters