Migrants amassed at the Greek-Turkish border made about 9,600 attempts to enter Greece overnight, Deputy Defense Minister Alkiviadis Stefanis said Sunday.
All attempts were successfully thwarted, Stefanis said before leaving for the border area.
At the border crossing of Kastanies, there are at least 3,000 migrants waiting to cross into Greece, authorities estimate.
There was tension throughout the night, culminating at about 2 a.m. when numerous young migrants tried to enter Greece from a point just north of the border crossing where there is no fence.
Greek army and police got wind of the attempt almost half an hour before it took place and prevented the crowd from crossing.
Also, about 220 migrants and refugees arrived during the night on the island of Lesvos by boats.