Interviews and a document obtained by The Associated Press show that Turkish officials have tentatively begun enforcing long-dormant rules governing Syrians' travel within the country.

So far the moves appear ad hoc and limited. But one academic says it is a sign of a more determined effort by Turkey to get a handle on the country's massive refugee population.

Ahmet Icduygu, who directs the Migration Research Center at Istanbul's Koc University, said it was the first time he'd heard of restrictions on travel by Syrians.

The one-page Interior Ministry document orders checks on Syrians' documents at the entrance and exit to each province and carries a warning to transport companies that Syrians need permission to leave the province where they registered.

The document's authenticity was confirmed by two government officials.