Christians protesting against an attack on a church clashed with military police, witnesses and security sources said, in fighting that spread across the downtown area.
Tahrir was the epicentre of the February uprising that overthrew former President Hosni Mubarak.
The curfew would last from 2am to 7am (0000-0500 GMT) on Monday, state TV reported. (*)
Editor: Kunto Wibisono
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