Turkish border guards have shot dead at least eight Syrians, including four children, who were trying to cross into Turkey, activists said.
A further eight people were injured, said the Syrian Observatory for Human Rights, a United Kingdom-based monitoring group.
It happened at a border crossing north of the Syrian town of Jisr al-Shugour, which is controlled by jihadist groups.
The Turkish military insists guards fired only warning shots and that the Syrians dispersed.
BBC revealed that Turkey said it is being unjustly accused, and is under immense pressure from the European Union to stop Syrians trying to travel to Europe.
More than 2.7 million people who fled the war in Syria have taken refuge in Turkey.
Turkey closed its borders to Syrians several months ago.
The Associated Press news agency quoted a senior Turkish official as saying: “We are unable to independently verify the claims” regarding the shooting, but said authorities were investigating.
As well as four children, three women and a man were also killed, the Observatory said.
Other Syrian opposition groups put the death toll at 11.
Since the beginning of 2016, nearly 60 civilians have been shot while trying to flee across the border from Syria into Turkey, the Observatory says.