A Palestinian court has extended the detention of a prominent activist who criticized the autonomy government of President Mahmoud Abbas.

Farid al-Atrash, the lawyer of Issa Amro, said Thursday that the court had extended his client's detention for four days.

He says Amro is being held under a recent edict that allows the government to crack down on social media critics. In a Facebook post, Amro criticized the detention of a local journalist who called for Abbas' detention.

"This is a black day in the history of the Palestinian judicial system and for Palestinian freedom of expression," al-Atrash said.

Amro was detained on Monday and has been on a hunger strike since then. Amro, 35, also faces charges in an Israeli military court. His trial is to resume in October.