ISTANBUL, Feb. 16 (Xinhua) -- A court in Istanbul on Friday sentenced six Turkish journalists to aggravated life imprisonment each over their alleged involvement in a failed coup in July 2016, local media reported.

The defendants, including Turkey's well-known journalists Nazli Ilicak, Ahmet Altan and Mehmet Altan, were charged with trying to remove the constitutional order, the state-run Anadolu news agency reported.

Turkey believes that the coup attempt, in which 250 people were killed, was orchestrated by the network led by the U.S.-based Turkish cleric Fethullah Gulen.

More than 150,000 officials and officers have been dismissed or suspended from their posts while over 55,000 others arrested in the ongoing investigation and crackdown, according to press reports.