According to the state news agency, at least 13 regime soldiers were killed when their bus came under attack in the east of Syria on Monday.
The attack took place in the northern countryside of Raqqa province, which is controlled by the PKK\YPG terrorist group, according to the agency.
Two other soldiers were injured in the attack.
In the past, several buses carrying regime soldiers had come under missile attacks, the most recent of which was on May 13. Ten soldiers were killed and nine others were injured during this attack.
No group has yet claimed responsibility for the attack.