Croatia has filed a complaint against its EU neighbor Slovenia over the construction of a razor-wire fence along their national borders which is designed to control a migrant flow but Croatia says has also endangered wildlife.

In a letter to the European Commission, the EU's executive body, Croatia said the fence is an obstacle for the migration of wild animals and Slovenia is violating European legislation on the conservation of natural habitats and the environment.

The most widely reported victims are deer that have died after becoming tangled in the barriers

Croatia has been annoyed by the construction of the fence between the two EU neighbors. Slovenia has so-far completed some 140 kilometers.

Hundreds of thousands of migrants fleeing wars and poverty have transited through the region since summer.