"More than 20,000 prisoners started the hunger strike in more than 114 detention centers and prisons," said Director of Egyptian Center for Human Rights Victims Haytham Abo Khalil, as cited in a Friday report by Anadolu Agency.

He added that the strike is aimed at protesting what he described as the "mistreatment" inside Egyptian prisons.

Abo Khalil said by staging the strike, the prisoners want to draw attention to their sufferings inside the Arab nation’s prisons.

A recent report by the Egyptian Center for Economic and Social Rights (ECESR), a local NGO, documented over 21,000 alleged cases of individuals who had been subject to prosecution since the July 3 ouster of elected president Mohamed Morsi by the military under the leadership of former general and now president-elect Abdel-Fattah al-Sisi.

There have been reports of widespread and systematic mistreatment and torture being carried out in Egyptian detention facilities.

Egyptian authorities often deny claims of maltreatment inside prisons.

The military-backed government also denies the presence of any "political" prisoners in the nation's jails, saying the thousands arrested since Morsi's ouster face criminal charges.

Egyptian military-installed authorities have launched a harsh crackdown on supporters of Morsi and his Muslim Brotherhood group, killing hundreds and rounding up thousands.

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