Days ahead of the elections, Turkey has put Fethullah Gulen - an influential cleric who is in self-imposed exile in the US - on the most wanted terrorist list along with the Isis and PKK.

Other names in the list include the founder of PKK Cemil Bayik, acting leader Murat Karayilan and senior figure Duran Kalkan, according to Anadolu agency.

Isis members believed to behind the deadly suicide bombing in Ankara that killed 102, also are on the list.

In total, the names and details of 728 people are on the list and they are ranked in five colour-coded categories from red - the most wanted - through to blue, green, orange and grey, according to AFP.

President Recep Tayyip Erdogan's arch-nemesis Gulen currently lives in a self-imposed exile in Pennsylvania.

The release of the list coincided with a massive crackdown on  a newspaper and TV studio in Istanbul that are critical of Erdogan's party and share links with Gulen's movement.

The development has come just days after Turkish government hired the services of a UK-based law firm to probe the worldwide activities of Islamic cleric Fethullah Gulen's Hizmet (Service) Movement.

Robert Amsterdam, founding partner of London-based Amsterdam and Partners LLP, said in a statement that his firm was hired by the Turkish government "to expose allegedly unlawful conduct by the Gulen network worldwide".

"We're going to look into their activities throughout the United States, Africa and other regions where the network is active," Amsterdam, who held a news conference in Washington to make the announcement, told Reuters by phone.