Egypt's army-backed government detained the Muslim Brotherhood's leader on Tuesday after a bloody crackdown on his supporters, underscoring its intention to crush the movement that had propelled the country's first freely elected president to power.

Egypt is enduring its bloodiest week of internal strife since the monarchy was overthrown in 1952, with about 900 people killed, including 100 police and soldiers, after the authorities broke up Brotherhood protest camps in Cairo last Wednesday.