Dozens of tents were pitched in the middle of the square -- the epicentre of the protests which toppled president Hosni Mubarak in February.

Security forces will watch the rally from a distance to avoid possible clashes, an official said on Thursday, as Egypt's government warned against plots to cause chaos.

"Police and army officers will be stationed in the side streets, but there will not be any security presence on Tahrir Square," the security official told AFP.

The interior ministry, in coordination with the army, has decided not to deploy forces in the square after a series of violent clashes this week between protesters and security forces, the official said.

On Wednesday, the government urged all those taking part in the demonstration to "maintain the peaceful nature of the protest" warning against "plots aiming to incite chaos in order to tarnish”.

AFP