|Police and investigators at the scene of the accident in Macedonia. Photograph: Ognen Teofilovski/Reuters|
Migrants and refugees using the overland route from Greece to western Europe often walk on railway lines to guide them along their way and evade police. It is fraught with danger but considered a safer route than crossing from Libya to Italy via the Mediterranean, where more than 1,300 migrants are believed to have drowned in the past three weeks.
It is believed to be the highest death toll for such an accident in Macedonia.
The migrants had been heading north near the village of Rajko Zinzifov, where the tracks pass through a narrow gorge with the Vardar river on the right and steep rocky slopes to the left. The authorities said those who survived did so by clambering up the slope or clinging to bushes along the riverbank.
Ivo Kotevski, a police spokesman, said eight survivors who were uninjured and in the area when police arrived were detained and taken to Veles to be questioned by a prosecutor. The remaining survivors are believed to have fled.
The prosecutor handling the case, Slavica Temelkovski, said the migrants who were killed were aged between 20 and 30. There was no information on whether they were men or women and their identities remained unknown. She said the victims would be buried in a Muslim graveyard in Veles.
Local media reported five similar incidents along train tracks which left six migrants dead in November and December last year.
Tens of thousands of migrants and refugees attempt to reach western Europe each year by heading from Turkey to nearby Greek islands. They then try to sneak on to ferries bound for Italy or head overland through Macedonia or Albania.
Although short, the sea journey from the Turkish coast is also perilous, with smugglers often overloading unseaworthy boats with migrants. It is not unusual for the captain to abandon the vessel after it enters Greek waters to avoid being arrested. On Monday, a wooden yacht packed with about 90 migrants ran aground on the shore of Rhodes, leaving three people dead, including a young boy.