Mongolian authorities on Friday grounded a suspected Turkish air force jet after witnesses said assailants snatched a man associated with the group headed by US-based preacher Fethullah Gulen.

Veysel Akcay, when asked who was behind his alleged abduction attempt, simply said: "I don't know."

The 50-year-old is director of a school in Mongolia that is alleged to be associated with Gulen, although teachers there denied the connection in response to questions by AFP.

"We're very uncomfortable with the fact that Friday's events... are being presented as a kidnapping operation," Turkish foreign ministry spokesman Hami Aksoy said in a statement.

"All such claims are false and we reject them."

As many as five men grabbed Akcay from outside his home in Mongolia's capital Ulaanbaatar Friday morning and threw him into a minibus, according to friends and eyewitnesses.

Mongolian vice foreign minister Battsetseg Batmunkh warned Turkish embassy officials on Friday that any attempt to abduct a person from Mongolia's territory would constitute "a serious violation of Mongolia's independence and sovereignty".

The plane in question eventually took off late Friday without Akcay on board.

The aborted coup in Turkey in July 2016 was blamed by authorities on the Gulenist movement -- a group outlawed as "terrorist" by Turkey -- and prompted the biggest purge in the country's modern history, including the detention of some 80,000 people.

Gulen denies any links to the coup bid and insists he leads a moderate Islamic group.

The interior ministry on Monday said 50 alleged Gulenists had been "delivered" to Turkey from the Turkish-speaking part of the island of Cyprus, according to the state-run Anadolu news agency.