Turkish authorities on Friday ordered the arrest of over 200 military personnel in new raids against suspects linked to the attempted coup in 2016, state media reported.
The Istanbul public prosecutor ordered arrest warrants for 219 soldiers on active duty including four colonels and five lieutenant colonels, state news agency Anadolu said.
Istanbul police launched an operation to capture the suspects on Friday morning.
They are believed to have ties to the group led by US-based Muslim preacher Fethullah Gulen, a former ally turned foe of President Recep Tayyip Erdogan.
Ankara accuses Gulen of being behind the failed coup but he strongly denies any links.
In Ankara, the capital's public prosecutor issued arrest warrants on Friday for 48 people, mainly working in the arms industry, also over alleged links to Gulen.
Turkey refers to the group as the "Fethullah Terrorist Organisation" but followers insist they have peaceful goals of promoting Islam and secular education.
Over 50,000 people have been arrested since the failed putsch in a purge lambasted by human rights activists and Ankara's Western allies.
Nearly 130,000 public sector workers have been sacked.
Last week, dozens of people including airforce personnel were detained for suspected links to coup-plotters in nationwide operations.
Turkish officials insist the raids are necessary to cleanse state institutions of the "virus" of infiltration by the Gulen movement.