SKOPJE, Macedonia (AP) — They huddle on the Greek border, awaiting a chance to sneak into Macedonia. Other migrants who make it across this landlocked country into Serbia are being deported back.

It means that Macedonia is being sandwiched by migrant pressure from Greece to the south and Serbia to the north — as these desperate people seek to reach Western Europe.

Police say about 18,000 migrants have been registered passing through Macedonia in a last month. Syrians account for nearly 13,000, and most of the migrants are male. Among them were about 2,000 children.

Macedonia has become a major transit route for Middle Eastern and African refugees. At least 25 have been killed by trains since January walking on railway tracks. Many are robbed by criminal gangs.