Dozens of people were hurt on Sunday when police fired tear gas on a group of migrants as they tried to break through a fence on the Greece-Macedonia border, the medical charity Doctors without Borders (MSF) said.

"Dozens of people were hurt, mainly suffering respiratory problems, and three had to be taken to hospital," MSF official Achileas Tzemos told AFP of the incident near the Idomeni crossing.

A Macedonian police source said three officers were also injured by stones thrown by the protesting migrants.