At least one person was killed and more than 600 injured in clashes between riot police and protesters in Cairo's Tahrir square on Saturday after a protest demanding the ruling military transfer power swiftly to a civilian government.

Police pulled down tents of about 100 protesters who had camped in the square overnight after a demonstration on Friday of about 50,000 people, mostly Islamists, against the military leadership.

Protesters later poured into the square and clashes erupted. State news agency MENA cited the health ministry's spokesman as saying the violence had injured 676 people.

Ahmed Mahmoud, a 23-year-old demonstrator, died in hospital after receiving a bullet wound, MENA said.

(Reporting by Shaimaa Fayed; Editing by Janet Lawrence)