Egypt's President Mohamed Morsi vowed security forces will "act with utmost decisiveness" to protect state buildings, as protesters clashed with police outside the presidential palace yesterday.

The presidency, in a statement posted on his Facebook page, also said it would hold "politically accountable" opposition groups behind the violence.

It said protesters had tried to break down the palace gates and scale its walls, and demanded that opposition groups denounce the violence and call on their followers to withdraw.

The opposition National Salvation Front, which called for mass rallies yesterday, said it "had no connection whatso-

ever with the trouble that erupted suddenly in front of the presidential palace."

It said the NSP condemned all acts of violence and urged security forces to exercise "utmost restraint” with the protesters.

People took to the streets in a show of opposition to Morsi and his Muslim Brotherhood after a wave of deadly unrest swept the country last week in the worst violence since Morsi was elected president last June.

The opposition accuses Morsi of betraying the revolution that toppled Mubarak two years ago.

The Republican Guard appealed for calm as demonstrators hurled petrol bombs over the palace walls and security forces responded with water cannon and tear gas and troops fired warning shots into the night sky.