The Russian and Syrian armed forces conducted a special joint military operation aimed at Islamic State (IS) terrorists in Syria, who were involved in a bombing that targeted a bus in Damascus, Syria, Major General Oleg Egorov, deputy head of the Russian Reconciliation Center for Syria, said on Sunday.

"A Russian military group, in cooperation with the units of Syrian state security and armed forces, carried out a special operation in the city of Jasim in Syria's southern Daraa Governorate," Egorov added.

The Russian military official revealed that the operation was conducted with the aim of "eliminat[ing] IS militants involved in the terrorist act of October 13, a bomb attack on a bus with the soldiers of the fourth tank division of the Syrian armed forces in Damascus province, which killed 19 and wounded 22 people."

20 IS fighters were killed as a result of the operation, including four militants who plotted the bus attack, he underlined.

Syrian outlet Sham FM reported Thursday that at least 18 Syrian soldiers were killed, and more than 20 were wounded when an explosive device detonated on a military bus in the Damascus countryside.

In mid-May, an attack by extremists in the Aleppo countryside left 12 Syrian army soldiers martyred and injured 14 others.

In early March, the Syrian Defense Ministry reported that 13 Syrian soldiers were martyred and another 18 injured in a terrorist attack that targeted a bus in Tadmor.