Updated: January 25, 2015 2:24 PM ET | Originally published: January 25, 2015 1:37 PM EST

Protests continued in the streets of Cairo on Sunday, following the death of a socialist activist who was shot and killed at a rally Saturday marking the fourth anniversary of the Tahir Square uprising that overthrew Egyptian president Hosni Mubarak.

At least 18 were killed in protests across the city as police officers opened fire, according to the New York Times. Security forces had been deployed across the city in an attempt to prevent a repeat of the dozens of deaths during last year’s anniversary.


Write to Justin Worland at justin.worland@time.com.