CAIRO — Egypt on Monday freed a prominent photojournalist who had spent five and a half years in prison for taking pictures during a crackdown in 2013 that culminated in the killing of more than 800 protesters.

The photojournalist, Mahmoud Abou Zeid, known as Shawkan, was returned to his family home in Cairo, where he vowed to continue working despite a five-year probation that requires him to spend every night at a police station.

“I can’t describe how I feel,” he told Reuters soon after his release at dawn. “I am free.”

Mr. Abou Zeid was probably the best-known of the dozens of Egyptian journalists jailed under President Abdel Fattah el-Sisi, who has slowly suffocated free speech since he came to power in 2013. Mr. el-Sisi has muzzled critical news outlets and, of late, expelled or refused entry to foreign reporters.

While in prison, Mr. Abou Zeid has received numerous international awards; last year, he won the Unesco Press Freedom Prize. That award drew fury from the Egyptian authorities, who said Mr. Abou Zeid was suspected of being a terrorist; the Foreign Ministry blamed Qatar for promoting his cause — a common Egyptian response to outside criticism.