Human Rights Watch has criticized Egyptian authorities for using excessive force against protesters marking the fourth anniversary of the 2011 revolution.

Sarah Leah Whitson, the director of the New York-based organization’s Middle East and North Africa division, said on Monday that Egyptian security forces “are still killing protesters on a regular basis” four years after the revolution.

The statement came after at least 23 people were killed in two days of protests, during which security forces used force to disperse anti-government protesters in Cairo and other cities.

She also called for an independent investigation into the authorities' excessive use of force to quell peaceful protests.

“While President [President Abdel Fattah] el-Sisi was at Davos burnishing his international image, his security forces were routinely using violence against Egyptians participating in peaceful demonstrations,” Whitson added.

Tensions have been running high for more than a year now, since the military ousted President Mohamed Morsi in July 2013 and launched a heavy-handed crackdown on his supporters.

Egyptians launched a revolution in January 2011, bringing an end to the nearly three decades of rule by former dictator Hosni Mubarak in February 2011. In an election after Mubarak’s ouster, Brotherhood-backed Morsi was elected president.

The Egyptian government has been cracking down on any opposition since Morsi was ousted, and Sisi has been accused of leading the suppression of Morsi supporters, as hundreds of them have been killed in clashes with Egyptian security forces over the past year.