An Egyptian judiciary official says a team of journalists working for satellite news broadcaster Al-Jazeera English will be held for 15 more days pending investigation into allegations they are part of a terrorist group.

Prosecutors accuse them of setting up an illegal media center aimed at tarnishing Egypt's image and spreading false news. Egypt's interim-backed military government accuses the Qatar-based broadcaster of being biased in favor of the Muslim Brotherhood, which authorities have branded a terrorist organization. The broadcaster repeatedly has demanded the reporters be freed.

The journalists, arrested Dec. 29, include Australian correspondent Peter Greste, Egyptian-Canadian acting bureau chief Mohammed Fahmy and Egyptian producer Baher Mohamed.

The official, who spoke on condition of anonymity as he wasn't authorized to brief journalists, said the detention order was issued Thursday.