An Egyptian researcher and journalist imprisoned on charges of being a member of the banned Muslim Brotherhood says he and eight other jailed reporters have begun a hunger strike to protest the conditions of their detention.

In a post Saturday on his Facebook page, Hesham Gaafar says he and the others are being mistreated and denied basic needs and visitation rights in the maximum security ward of Cairo's Tora prison.

Gaafar was arrested last October in a raid on his Mada Foundation NGO, which worked on democratic participation and journalism training, and has been held in solitary confinement.

Egypt has arrested dozens of journalists in a sweeping security crackdown over the past years, and academics say they too have been targeted by police and censors.