The leader of Sinai Province, a terrorist group in Egypt with links to the Islamic State,on Wednesday called on followers to attack local judges, Reuters reported.
The call was made in an audio statement posted on a prominent jihadist website.
It appeared days after six members of the group were executed for an attack on soldiers in Cairo last year, and follows a court's decision on Saturday to seek the death penalty for ousted Islamist President Mohammed Morsi.
"It is wrong for the tyrants to jail our brothers," cleric Abu Osama al-Masry was quoted as having said, referring to judges.
"Poison their food... surveil them at home and in the street... destroy their homes with explosives if you can," he added.
Reuters could not confirm the authenticity of the recording.
Sinai Province, formerly known as Ansar Bayt Al-Maqdis, is a Sinai-based terrorist group that has claimed responsibility for most of the terrorist attacks in the region over the last few years.
Among the attacks claimed by the group since Morsi's ouster was the assassination of a top Egyptian police general, who was gunned down as he left his home in a west Cairo neighborhood, and a bus bombing on a tour bus filled with South Korean tourists in the Sinai.
The Egyptian army imposed a curfew on Gaza on October 25, following two deadly attacks in El-Arish, which killed dozens of soldiers and which were also claimed by the group.