Prosecutors in Istanbul issued arrest warrants for 271 soldiers, 122 of whom are still on active duty, as part of a probe into followers of US-based Muslim cleric Fethullah Gulen in the Turkish armed forces, news agency Anadolu reported.

Turkey has accused Gulen of ordering the attempted overthrow of President Recep Tayyip Erdogan on July 15, 2016 -- a charge he strongly denies.

The raids were spread across 47 provinces, including the western province of Izmir, where prosecutors issued 75 warrants as part of an investigation into a Gulen "cell inside the armed forces", the agency added.

Over 77,000 people including military personnel have been arrested over alleged Gulen links under the post-coup state of emergency imposed nearly two years ago.

Ankara's Western allies including the European Union have expressed concern over the scale of the purge which has seen more than 140,000 people suspended or sacked from the public sector, including judges, soldiers and police.

But Ankara insists the raids are necessary to remove the "virus" of caused by the Gulen movement's infiltration of key Turkish institutions.

Gulen, who has lived in self-imposed exile in Pennsylvania since 1999, insists his movement is peaceful and promotes moderate Islam.