EGYPT'S president has signed a new bill into law restricting rallies and other public gatherings, a move likely to raise fresh questions about the army-backed government's democratic credentials.

Thousands of anti-government protesters were on the streets of Cairo and other cities when the new bill was announced on state media, as they have been regularly in the nearly three years since autocrat Hosni Mubarak was ousted.

The new legislation will reportedly require them to get advance permission from the police before gathering in the future.

President Adli Mansour's approval of the law came as a committee prepared to vote on an amended constitution that will be put to a referendum expected in coming months. Parliamentary and presidential elections are due next year.

Rights groups had urged Mr Mansour to reject the draft presented to him by the cabinet installed after the army overthrew Mr Mubarak's successor, Islamist Mohamed Mursi, in July.

"The draft law seeks to criminalise all forms of peaceful assembly, including demonstrations and public meetings," a statement by 19 Egyptian organisations said.

Thousands of supporters of Mr Mursi and his Muslim Brotherhood demonstrated in several cities yesterday, marking 100 days since security forces crushed two pro-Mursi sit-ins in Cairo, killing hundreds. Police fired tear gas to disperse some of the demonstrations.