Turkish academics are instructed not to travel abroad on assignments, the Council of Higher Education announces.
Academics who are currently abroad and do not have a compelling reason to stay outside the country, should return, it says.
New checks were being imposed to uncover any links between staff and the Gulenist movement. One academic said staff were being told to resubmit their qualifications.
"It's a temporary measure that we were compelled to take due to flight risk of alleged accomplices of coup plotters in universities," says a government official, warning that "certain individuals are believed to be in contact with cells within [the] military."