Turkey may have to build new courthouses to cope with thousands of prosecutions over July's failed coup, Justice Minister Bekir Bozdag has said, as the number of arrests reached 32,000.

Authorities have detained or sacked people from across local government, the military, the media and the judiciary, and asked the United States to deport cleric Fethullah Gulen, accusing him of organising the aborted uprising.

"We will build new courthouses as needed," Mr Bozdag told private broadcaster NTV in comments aired live.

He said he did not expect mass trials with "thousands of defendants" and added that some of the 32,000 people in custody over links to Mr Gulen could be freed as the legal process advanced.

Trials would take place in cities across the country and not in one single venue, he added.

The numbers of those arrested marks an increase of more than 10,000 from those previously given by the government.

Mr Bozdag said that there could be new arrests, while some of those currently arrested could still be freed under judicial control or freed entirely.

US officials have promised to respond to the extradition request for Mr Gulen in a couple of days, he added.

The US has said it is cooperating with Turkey and asked its NATO ally for patience as it processes the extradition request for the 75-year-old preacher.

Mr Gulen, a former ally of President Tayyip Erdogan now branded a terrorist by the Turkish government, denies any involvement.