Hundreds of angry mourners have flocked to the funeral of Shaimaa El-Sabagh, who was shot dead at a protest in downtown Cairo on Saturday, in her hometown of Alexandria.
El-Sabagh, 33, was an advocate for workers' rights and a leading member of the Socialist Popular Alliance Party in Alexandria, a group which supported both the January 25 revolution and the June 30 anti-Brotherhood protests.
She was heading, with around two dozen marchers, to Tahrir Square to lay flowers in the memory of those who died during the 25 January 2011 uprising.
She is survived by her five-year-old son and husband.
Forensic Medicine Authority spokesperson Hesham Abdel-Hameed said El-Sabagh died from a birdshot injury, which was shot at a distance under eight metres.
The wound caused significant damage to her lungs and heart and caused bleeding in the thoracic cavity, he added.
The prosecutor general has summoned police personnel who dispersed the demonstration for questioning and subpoenaed police records of the event.
Following the incident, the interior ministry denied accusations by marchers that a policeman had gunned El-Sabagh down.
Police said marchers attacked them with fire crackers.
However, the Socialist Popular Alliance Party said in a statement that their march was peaceful.
Members of the party said the march was not authorised by the police but was announced in advance.
A law passed by the interim authorities in late 2013 bans all demonstrations not pre-approved by the police, resulting in the arrest of many protesters despite condemnation from freedom of expression advocates.
The minister of interior had recently said that all violations of the law on fourth the anniversary of the revolution that toppled autocrat Hosni Mubarak would be dealt with swiftly and firmly by the police.