Egyptian security forces arrested dozens of protesters in Cairo following an anti-government rally on Wednesday. At least 43 protesters were detained near the capital's iconic Tahrir Square, according to an anonymous security official interviewed by the Associated Press.

The rare demonstration marked the third anniversary of the Mohammed Mahmoud battle, named for the Cairo street on which nearly 50 protesters were killed in clashes with police in November 2011. The incident became known as one of the most brutal acts of police aggression in the aftermath of Egypt's 2011 uprising that led to the ouster of dictator Hosni Mubarak.

Activists had planned to rally on Wednesday in defiance of the country's repressive protest laws, enacted by the military-backed government of President Abdel Fattah al-Sisi. Eyewitness reports from the independent Egyptian news site Mada Masr suggest that plainclothes officers had been deployed in downtown Cairo since early morning, alongside a more visible mobilization by uniformed security. Plainclothes officers later began arresting protesters and apparent bystanders alike, including nearby cafe patrons and anyone with a backpack. Some undercover officers had infiltrated the demonstration wearing Guy Fawkes masks, the Egyptian news site Daily News Egypt also reports.

The protesters were largely non-Islamists, according to the AP. Indeed, some of the groups responsible for commemorating the anniversary, including the liberal grassroots Kefaya Movement, made a point of dissociating themselves from the banned Muslim Brotherhood party. The Islamist group was ousted from government by al-Sisi in July 2013 and a year later banned entirely.

Egypt has been criticized for its crackdown on dissent by human rights organizations, but leftist political parties have been cautious about publicly challenging the al-Sisi government. A spokesman for Egypt's Revolutionary Socialist party told Mada Masr that while his group has limited street protests, it has nonetheless maintained the importance of marking revolutionary milestones like the Mohammed Mahmoud protests.