By Shadi Bushra
CAIRO (Reuters) - A woman protester was shot dead in central Cairo on Saturday, security sources said, one day before the anniversary of the popular uprising that ousted autocrat Hosni Mubarak in 2011.
Although a security crackdown since 2013 when the army toppled Islamist president Mohamed Mursi has virtually ended street demonstrations, several took place this week in Cairo and Egypt's second city Alexandria.
The security sources said the protester was shot with birdshot near Tahrir Square, the symbolic heart of the 2011 revolt that ended 30 years of iron-fisted rule under Mubarak.
Photographs on Twitter showed members of Egypt's security forces with black masks standing in the area where the woman, liberal activist Shaimaa Sabbagh, was shot.
The Socialist Popular Alliance said on its Facebook page that party member Sabbagh was killed by security forces. A witness said protesters were carrying flowers to Tahrir Square when the shooting occurred.
Prime Minister Ibrahim Mehleb said in a statement an impartial investigation would find whoever killed Sabbagh, the state news agency reported.
In a scheduled televised address on Saturday evening, Abdel Fattah al-Sisi praised the desire for change that had sent Egyptians into the street four years ago, but said it would take patience to achieve all of "the revolution's goals".
He did not mention the shooting.
While former army chief Sisi has taken steps to improve Egypt's economy, human rights groups accuse him of restoring authoritarian rule to the most populous Arab state.
Opponents say new laws, including one restricting protests, have rolled back freedoms won in the uprising. Islamists and liberal activists, including many who supported Mursi's removal, have been jailed.
The government says it is committed to democracy.
An Egyptian court ordered the release of Mubarak's sons Alaa and Gamal on Thursday pending a retrial in a corruption case.
In November, a court dropped charges against Mubarak of conspiring to kill protesters in the uprising, raising fears among activists that the old guard was making a comeback.
(Writing by Michael Georgy; Editing by Robin Pomeroy)