Police in northern Greece say 214 Syrian refugees have been detained after crossing a river that forms a natural border with Turkey.

Wednesday's announcement marked the second recent mass crossing of the Evros River — 107 refugees were detained in the same border area last week.

A police official told The Associated Press that refugees and other migrants were taking advantage of current low river levels near the border town of Orestiada. The official was not authorized to speak to the news media and asked not to be identified.

Migrants are seeking alternative routes to the European Union after a crackdown on crossings to the Greek islands started in March, as part of an agreement between the EU and Turkey to stop the flow of migrants and refugees to Europe.