Police say they have detained 20 people after a clash involving some 100 migrants in northwestern Bosnia injured scores, including three policemen.

Spokesman Ale Siljdedic says trouble erupted early on Wednesday in a migrant center in Velika Kladusa when groups of migrants turned against each other, using bottles, rocks and other objects.

Siljdedic says migrants attacked a patrol that came to the scene, prompting police to send in reinforcements. He says police have since remained in the center as tensions persist.

A fire last weekend damaged part of the facility in Velika Kladusa that hosts some 500 migrants. Siljdedic says at least six of the detained now face deportation.

Thousands of migrants are stuck in Bosnia as they look for ways to move toward the West.