Two people have been killed in clashes, and nine wounded in a bomb blast on a train, as police quash protests marking the anniversary of Egyptian president Mohamed Morsi's ousting.
The violence came as the pro-Morsi Muslim Brotherhood-led Anti-Coup Alliance issued an aggressive rallying cry demanding a "day of anger" to mark the occasion.
Nine people were wounded when a bomb hidden in a briefcase near a passenger seat exploded inside a train compartment in the Mediterranean city of Alexandria late on Thursday, security officials and state media said.
One person was killed by gunshot during clashes in a Cairo district as pro-Morsi supporters clashed with police, while a police officer was killed also by gunshot when his checkpoint was torched by protesters in the capital, security officials said.
Three other police also suffered burn injuries when the checkpoint was torched.
Police closed off several main squares in Cairo and scoured neighbourhoods to head off protests earlier on Thursday.
In the capital's Ain Shams district, black-clad riot police fired tear gas and shotguns to disperse a few dozen protesters who burned tyres on a road. Police also broke up protests elsewhere in Cairo.
Thirty-nine wanted activists were arrested ahead of Thursday's protests, and 157 allegedly illegal demonstrators were detained during the day, the interior ministry said.
The Muslim Brotherhood was listed as a terrorist group after Morsi's overthrow on July 3, 2013 and many of its leaders, including the ex-president himself, have been jailed and are on trial.
The ex-army chief who toppled him, Abdel Fattah al-Sisi, has been elected to replace him.
Security forces were also on high alert for further bombings, days after two senior police were killed when devices they were defusing outside the presidential palace exploded.
Since Morsi was deposed after a turbulent year in power, at least 1,400 people, mostly his Islamist supporters, have been killed in street clashes and more than 15,000 imprisoned.