One of last migrants cross the border line between Hungary and Serbia near Roszke village on September 14, 2015. (AFP Photo)
The main official border crossing point between Serbia and Hungary was closed to migrants on Tuesday, an AFP correspondent on the scene said.
After it sealed the main entry point used by migrants the previous day, Hungary had continued to let them enter through an official border entry post around 2 kilometres further down.
But at midnight, it shut this route as well, and hundreds of migrants were left to queue with no apparent hope of entering.
"The border was shut and has yet to re-open," said UNHCR spokesman Babar Baloch from the border.
"Our staff do not have access, and the Hungarian authorities have not let us know about any schedule they have for re-opening the border," he added.
Hungarian police claimed that a record 9,380 people entered Hungary on Monday -- almost twice as many as the previous records set last week -- although this did not fit with information from AFP reporters at the scene, who saw far fewer migrants at the border than previous days.
Those who had made it through the border before it shut were taken by bus to a train station at the border town of Roszke and loaded on to trains.
Unconfirmed reports suggested they were being taken to the Austrian border.