At least 13 Syrian regime soldiers were killed and two were injured in the attack, according to local media.
At least 13 regime soldiers has been killed when their bus came under attack east of Syria, according to the regime's news agency SANA.
SANA said the attack took place on Monday in the the Jabal al Bishri region - northern countryside of Raqqa province - which is controlled by the PKK\YPG terrorist group.
Two other soldiers were injured in the attack.
No group has yet claimed responsibility for the attack.
Several buses carrying regime soldiers had come under missile attacks in the past, the last of which was on May 13 in which ten soldiers were killed and nine others injured, according to reports.
Syria's 11-year-old war has carved the country into various zones of control, with regime troops and allied fighters controlling the most territory.
One of the deadliest bus ambushes was in December 2020, when 28 people were killed in an attack on a main highway in Syria's eastern Deir Ezzor province.