Egypt's opposition is to hold mass rallies nationwide on Friday, marking the second anniversary of a revolt that toppled Hosny Mubarak, to protest at President Mohammed Morsi's policies and his Islamist-backed government, dpa reported.
The protests are to be led by the main opposition bloc, the National Salvation Front, demanding a repeal of an Islamist-drafted constitution that was approved in a controversial referendum in December.
The mainly secularist bloc claims the charter could undermine fundamental rights and that the vote was marred by massive irregularities.
The main rally is to be held in Cairo's iconic Tahrir Square, the epicentre of an 18-day uprising that eventually forced Mubarak to step down in February 2011.
Protesters also plan marches to the presidential palace in Cairo, where dozens of Morsi's opponents have been camping since early December in protest at the constitution.
Morsi's Islamist allies have said they will stay away to avoid clashes with opponents.
At least six people were killed in December in violent protests outside the presidential palace.
The authorities are to tighten security around state institutions and police buildings fearing possible attacks, local media reported Thursday.
Morsi, of the powerful Muslim Brotherhood, took office in June as the country's first elected civilian president.
The opposition accuses him of tightening his group's hold on power and failing to revive an ailing economy.