A terrorist attack on a bus in Damascus, March 2017. (AFP)

The Syrian Defense Ministry reported on Sunday that 13 Syrian soldiers died and another 18 got injured by a terrorist attack that targeted a bus.

"A bus with troops has been attacked by terrorists armed with various weapons. As a result, 13 troops, including officers, have died, 18 have been injured," according to the Ministry in a statement.

The terrorist attack unraveled at 1:30 PM near Tadmor, in a desert area.

US-backed SDF shoot dead two Syrian soldiers

Last week, a Syrian military source reported to Al Mayadeen that two soldiers, including an officer, were shot dead in an SDF attack.

A Syrian military source said that around 2:00 Tuesday afternoon, a US occupation patrol, accompanied by a group of SDF militia members, tried to infiltrate the Syrian army checkpoints in the village of Ghozaliya in Tal Tamr countryside in Al-Hasakah Governorate.

According to the source, the Syrian army prevented the American patrol from entering and forced it to return.

Shortly afterward, according to the source, SDF militia attacked the aforementioned sites with machine guns and mortar shells, which led to the death of two soldiers, including an officer. Syrian soldiers responded and a number of SDF militia members were wounded.