Judiciary officials say two icons of Egypt's 2011 revolution that toppled Hosni Mubarak have been sent to trial on charges of taking part in an "illegal" protest and allegedly assaulting policemen.

They said prosecutors on Thursday sent the two — Ahmed Douma and Ahmed Maher — to trial, which will begin on Sunday.

The officials spoke on condition of anonymity because they were not authorized to speak to journalists.

This is the first referral of activists to trial linked to the recently enacted protest or assembly law, which places draconian conditions on staging street demonstrations.

Their trial is the latest turn in the turmoil engulfing Egypt since Mubarak's ouster, signaling a growing rift between the military-backed government and liberal activists five months after the ouster of Islamist President Mohammed Morsi.