13 killed during Egypt clashes
Supporters of Egypt's ousted Islamist president have fought street battles with police in Cairo and other cities on the fourth anniversary of the country's 2011 uprising, as clashes left 13 people dead and dozens injured.
Another two people died when an explosive device they were planting under a high-voltage tower in the Nile Delta exploded prematurely, security officials said.
Most of the deaths took place in Cairo's eastern Matariyah district - an Islamist stronghold where police clashed with supporters of the outlawed Muslim Brotherhood group. Nine protesters and one police officer were killed in the clashes.
The violence underscored the continued turmoil affecting the Arab world's most populous nation four years after the 18-day uprising that toppled autocrat Hosni Mubarak.
Two other protesters were killed elsewhere in Cairo, and one in the Mediterranean port city of Alexandria.
Two police officers were injured by shrapnel when a roadside bomb exploded in an eastern Cairo district and six more were wounded in the Matariyah clashes, according to the officials.
By early evening, debris covered the site of the Matariyah clashes and a cloud of tear gas hung over the area.
The Interior Ministry, which is in charge of the police, said a total of 134 protesters were arrested nationwide.
Cairo, a city of some 18 million people, appeared mostly deserted, with many residents staying home to avoid being caught up in any turmoil.
In downtown Cairo, supporters of Egyptian president Abdel-Fattah el-Sissi clashed with critics of the general-turned-politician in pitched street battles. Police later used tear gas to disperse the president's critics, who fled to side streets.
The protests and the stepped-up security came as activists mourned the death of a female protester shot in downtown Cairo while taking part in a gathering commemorating the nearly 900 protesters killed in the 2011 revolt.
Activists and her party blame police for the death of Shaimaa el-Sabagh, a 32-year-old mother of one from Alexandria. The government says it is investigating.
Videos posted online show Ms el-Sabagh, a member of the leftist Popular Alliance party, with other protesters carrying placards and chanting "bread, freedom and social justice" - the chief slogan of the 2011 uprising. She and others carried wreaths of flowers they intended to place at nearby Tahrir Square in memory of the fallen protesters.
In the videos, two masked, black-clad police officers point their rifles in her direction before gunshots ring out. The next frame has her on the ground.
Hundreds attended her funeral in Alexandria.
The prominent Hisham Mubarak Law Centre said in a Facebook post that five of Ms el-Sabagh's fellow protesters who had given investigators their account of the incident were themselves charged with assaulting police and taking part in an illegal demonstration.
Ms el-Sabagh's death is the second of a female protester in recent days. Islamist Sondos Reda was shot dead during a Friday protest in Alexandria. Activists also blame the police.