Serbian police say they have detained six people for smuggling 78 migrants trying to reach the European Union.

Police said they discovered the migrants in two separate incidents near the Bulgarian border. The statement says 37 migrants from Afghanistan and Pakistan were hidden in a van intercepted on a regional road. Another 41 people from Syria have been caught crossing illegally from Bulgaria, the statement says.

Serbia has announced stepping up efforts to stop the migrant influx, including forming joint police and army teams that will patrol the borders with Bulgaria and Macedonia. The country wants to avoid a migrant pileup after EU member Hungary recently introduced tough anti-migrant measures.

The Balkan route was closed in March, but the flow of migrants has persisted.