Turkish news reports say a court has ordered the formal arrest of four people detained in recent raids on a newspaper and a television station affiliated with the U.S.-based Muslim cleric Fethullah Gulen, a one-time ally of President Recep Tayyip Erdogan turned foe.

But the court on Friday ordered the release of Ekrem Dumanli, the editor-in-chief of one of the country's biggest newspapers, Zaman. The court banned Dumanli from traveling, pending possible charges.

The investigation has been widely condemned as a blow against free press, drawing criticism from the EU and the U.S. Erdogan has lashed out at the foreign criticism.

The four men in custody are the head of a media group, the former head of the anti-terror division of the Istanbul police and two other police officials.