Egypt's military-installed government has formally designated the Muslim Brotherhood as a terrorist organization, blaming it for a police headquarters bombing that killed 15 people.
A government minister said this will mean a ban on all the group's activities including demonstrations.
Authorities will have the power to charge any member of the movement with membership in a terrorist organization.
This marks an escalation in the army-backed crackdown on the Brotherhood since the ouster of Egypt's elected Islamist president Mohamed Morsi in July.
The Cabinet statement comes a day after the bombing of a police headquarters in the Nile Delta city of Mansoura.
The Muslim Brotherhood on Tuesday condemned that bombing, and on Wednesday, a hardline Islamist group based in the Sinai said it was responsible for the attack.
The al-Qaida-inspired group Ansar Beit al-Maqdis said the suicide car bombing was a response to the government's crackdown against Islamists.
Ansar Beit al-Maqdis has previously asserted responsibility for bombings in Sinai and the attempted assassination of Interior Minister Mohamed Ibrahim in Cairo in September.