Turkish authorities have dismissed nearly 28,000 teachers and suspended almost 9,500 others over alleged links to terrorism, a deputy prime minister said on Monday, pursuing a security crackdown followed a failed coup in July.

Turkey has sacked or suspended some 100,000 civil servants including judges, prosecutors, police officers and teachers since a group of rogue soldiers tried to topple the government. At least 40,000 people have been detained for suspected links to US-based cleric Fethullah Gulen, whom Ankara blames for the plot.

Gulen, who has lived in self-imposed US exile since 1999, has denied the accusations and condemned the coup. The scope of the crackdown has raised concern from human rights groups and Turkey's Western allies, who fear President Tayyip Erdogan is using the abortive coup as a pretext to curtail dissent.

Teachers in the largely Kurdish southeast of Turkey have been targeted in recent weeks, with authorities citing their alleged links to the outlawed Kurdistan Workers Party (PKK).

Speaking after a cabinet meeting, Deputy Prime Minister Nurettin Canikli said nearly 28,000 teachers had been expelled from the profession. Investigations of almost 9,500 suspended teachers were continuing, he said.

"As part of our fight against terrorism, necessary measures have been carried out on teachers along with other civil servants assessed to be linked with terrorist organisations," Canikli said.

He added that 455 teachers who had previously been removed from duty had been reinstated after inquiries were completed.

His comments coincided with the start of a new school term today, following the end of the summer holidays.

Immediately after the July 15 coup, authorities shut 15 universities and around 1,000 secondary schools linked to Gulen. The closures left some 200,000 students in academic limbo, wondering if they could continue their studies and worried about the black mark of a Gulen school on their college record.