While Hungary has repelled migrants at its southern border with Serbia with a razor-wire fence, those arriving from Croatia on its western border are instead greeted with buses and trains that escort them to Austria.

Hungarian Foreign Minister Peter Szijjarto told news portal index.hu on Sunday that migrants entering from Croatia are receiving the favorable treatment for now because Hungary doesn’t yet have a fence completed along its frontier with Croatia, whereas the fence with Serbia is complete.

Szijjarto explained that without a fence, expelling migrants back into Croatia would create chaos.

The result is that more than 16,000 migrants have crossed into Hungary from Croatia since Friday, whereas the Serb side of the border has been all but emptied of migrants.