Twenty Syrians were killed and over 60 were injured in a failed Scud missile test carried out by Syria, Iran and North Korea in May, Japan's Kyodo News reported on Friday.
One of two missiles had apparently strayed off its course due to a technical malfunction, landing in a civilian populated area in a town on the Syrian-Turkish border. The victims were all civilians.
The incident was part of a botched attempt to test a new short-range ballistic missile developed together by the three countries, the report said.
According to Kyodo News, the area - a marketplace - was immediately closed off to the public, who were told that a gas explosion had ensued and was the cause of the wreckage.
It was unclear where the other missile landed.
The Jerusalem Post could not confirm the report.