'Still some hope they will try to defuse it by political means'
2 August 2013 Last updated at 22:19 BST
Egypt's government has ordered police to block access to protest camps set up by supporters of ousted President Mohammed Morsi, state TV reports.
Thousands have been defying warnings from the authorities to abandon the sit-ins in Cairo outside the Rabaa al-Adawiya mosque and at Nahda Square.
Human Rights Watch earlier called on the state to "avoid another bloodbath".
The Anti-Coup Pro-Democracy Alliance, a grouping of Morsi supporters led by the Muslim Brotherhood, vowed that the protests would continue.
The BBC's Jim Muir is watching developments in Cairo.
This video was re-edited on August 5 to remove pictures that had been included in error.