Turkish authorities have released more than 30,000 prisoners, according to the country's justice minister, after Ankara said it was releasing inmates to make space for tens of thousands detained over suspected links to a July coup attempt.

Turkey has said it would release a total of 38,000 prisoners as part of its penal reforms in the wake of the coup that tried to topple President Tayyip Erdogan's government.

Justice Minister Bekir Bozdag said on a news conference on Friday that the exact number of inmates released so far was 33,838.

In a series of messages posted on Twitter on Wednesday, Bozdag said the move was "not an amnesty", and that convicts were not being pardoned but released on parole.

"The regulation refers to crimes committed before July 2016. The crimes committed after July 1, 2016, are outside its scope," Bozdag said.

"As a result of this regulation, approximately 38,000 people will be released from closed and open prisons at the first stage."

On Thursday, the government said it expelled nearly 43,000 people from their jobs in public institutions for alleged ties to banned organisations.

Lists of names and positions published by the official gazette on Thursday show the wide-scale purge Turkey has undertaken since the failed coup of July 15.

The government blamed the US-based cleric Fethullah Gulen for the plot that killed at least 270 people, and labels the network a terror organisation.

The dismissals are allowed through the state of emergency, declared following the coup attempt. The highest number of dismissals is from the Ministry of National Education with 28,163 people.

Some 35,000 people have been detained for questioning and more than 17,000 of those have been formally arrested to face trial, including soldiers, police, judges and journalists.