Turkey has accused its neighbour Greece of allowing 12 migrants to die in the cold by stripping them of their clothes and then pushing them back across the border.
The charges from Turkish Interior Minister Suleyman Soylu threaten to increase tension between the two amid other disputes.
Greece dismissed the accusations as "utter nonsense".
Mr Soylu posted blurred images on Twitter showing partially naked bodies lying by the roadside.
“Twelve of the 22 migrants pushed back by Greek border units” froze to death after being “stripped [of] their clothes and shoes”, he wrote.
The “EU is remediless, weak and void of humane feelings”.
Turkey fears EU countries are ignoring its concerns that its refugee camps near Syria will be overrun by desperate Afghans fleeing the Taliban after their return to power.
Mr Soylu said the images were taken near Turkey's western border town of Ipsala. The regional governor's office said 11 of the migrants were found frozen to death.
Another who was taken to hospital with frostbite “could not be saved and died”, the governor's office said without identifying the nationalities of the migrants.
Greece's Migration Minister Notis Mitarachi did not dispute the 12 deaths but dismissed Turkey's version of events as “false propaganda".
“These migrants never made it to the border. Any suggestion they did, or indeed were pushed back into Turkey is utter nonsense,” Mr Mitarachi said.
“Rather than pushing out unfounded claims, Turkey needs to live up to its obligations and work to prevent these dangerous journeys.”
Relations between the two hit crisis in 2020 as Turkey began exploring for natural gas in Eastern Mediterranean waters claimed by Greece and its fellow EU member, Cyprus.
The two sides continued to accuse each other of trying to escalate tensions by staging air and sea exercises around islands whose ownership has been under dispute for most of the past century.
These tensions have been compounded by Ankara's claims that Greece is breaching international conventions by intercepting migrant boats in the Aegean and then sending them back to Turkey.
The UN refugee agency estimates more than 2,500 people died or went missing at sea as they tried to reach Europe from North Africa and Turkey last year.
