Egyptian police arrested the main spokesman of the Muslim Brotherhood on Tuesday, charging him with inciting violence.
Gehad el-Haddad and several other senior Brotherhood members were picked up in a police raid on a Cairo apartment.
Haddad was the internationally-known face of the Brotherhood after senior member Mohamed Morsi was elected president in 2012. He continued to defend the Brotherhood and the president after Egypt's military removed Mr. Morsi from power in July.
Haddad went into hiding after the army's violent crackdown on pro-Morsi demonstrators.
The U.S. State Department criticized Haddad's arrest as political. It is urging Egypt's interim government to include all voices in the political transition.
Also Tuesday, an Egyptian court ordered the freezing of assets of a number of senior Brotherhood members. Much of the top Brotherhood leadership, including Mr. Morsi, are under arrest, charged with inciting violence.