Three European arms experts working with Syrian rebels were killed in the Syrian coastal city of Latakia, the pro-government Sham FM radio reported.
The report cited a military source as saying that the three engineers were working as experts in making rockets between the town of Kansaba and al-Rihanieh, Xinhua said.
The radio station gave no details about the nature of the military operation that led to the killing of the experts.
More than 100,000 people have been killed in the conflict in Syria, according to UN Secretary General Ban Ki-moon. Another 1.7 million Syrians have been forced to seek shelter in neighbouring countries.
Britain-based activist group Syrian Observatory for Human Rights said more than 2,000 people have died since the beginning of the holy month of Ramadan, BBC reported.
