The bodies of at least 68 young men and boys, all executed with a single gunshot to the head or neck, were found on Tuesday in a river in the Syrian city of Aleppo, a watchdog and rebels said.
A Free Syrian Army captain at the scene said at least 68 bodies had been found and that many more were still being dragged from the water, in a rebel-held area.
The bodies were found in the Quweiq River, which separates the Bustan al-Qasr district from Ansari in the southwest of the city, the Syrian Observatory for Human Rights said.
"Until now we have recovered 68 bodies, some of them just teens," said Captain Abu Sada, adding that all of them had been "executed by the regime."
"But there must be more than 100. There are still many in the water, and we are trying to recover them."
A volunteer said as he helped load one of the bodies on a truck: "We don't know who they are because there was no ID on them
At least 15 bodies could already be seen on the truck, with other continuing to arrive.
Abu Sada said they would be taken to the hospital at Zarzur where relatives could seek to identify them.
"Those who are not identified will be buried in a common grave."