Dozens of protesters are preparing for a sit-in outside the presidential palace to protest the constitutional declaration and planned referendum on the draft constitution.

An aide told Reuters that President Mohamed Morsy has returned to the palace Wednesday after leaving Tuesday night amid demonstrations that left nearly 30 civilians injured.

The Interior Ministry also announced Wednesday that 40 police officers had sustained cuts, bruises and fractures on Tuesday night, including the head of Cairo's Central Security Administration and a deputy chief police investigator.

Photos aired by State TV Wednesday showed protesters erecting tents, and a reporter for state news agency MENA said that 24 tents have been set up outside the palace.

Morsy was forced to leave after protests swelled outside the palace walls Tuesday evening, but by Wednesday morning only one Central Security car and one armored vehicle were stationed outside the back entrance.

Morsy’s 22 November declaration makes his decrees immune from judicial review. The president’s decision to call a referendum on the constitution draft has also stoked anger among opposition forces objecting to Islamist domination of the Constituent Assembly and the drafting process.

In a statement late Tuesday, the Constitution Party said it would stage a sit-in outside the palace until Friday, while calling for continuing marches and support for a parallel demonstration in Tahrir Square.

Police forces used tear gas against protesters Tuesday night as both sides clashed near the palace. A number of protesters removed barbed wires around the palace. Some demonstrators spray-painted slogans against Morsy and the Muslim Brotherhood on its walls.

Other demonstrators gave out leaflets condemning the draft of the new constitution: "The draft of the new constitution, laid down without political consensus, entrenches despotism, authoritarianism, social injustice, military guardianship," the documents read.