Six Iranian migrants have sewn their mouths shut during a protest near the village of Idomeni at the Greek-Macedonia border.
They took the drastic action as several hundred migrants, many from Iran and Morocco, protested for a fourth straight day at the border.
Macedonia and other Balkan countries have toughened the criteria for border crossings in the wake of the deadly November 13 attacks in Paris.
Meanwhile, Turkey's state-run news agency says authorities have recovered the body of a four-year-girl who was among a group of 10 migrants reported missing after a boat sank on its way to Greece.
The Anadolu Agency says the girl's body was discovered on Sunday among rocks in the resort of Bodrum.
She was identified as one of the 10 reported missing on November 18 by one of the five survivors, Anadolu said.
The migrant who identified her said a woman addressed the girl as "Sena" during their ill-fated journey to the Greek island of Kos, according to Anadolu.
Save the Children charity group says that more than 70 children have drowned trying to reach Greece since September.