At least 20 Daesh terrorists have been killed in joint “special operation” launched by Russian and Syrian forces in Dera’a province.

The operation took place in the town of Jasim in Syria's Dera'a Province, Russia's ITAR-TASS news agency reported, citing Deputy head of the Russian Reconciliation Center for Syria, Major General Oleg Yegorov as saying on Sunday.

The operation was performed by "Syrian forces supported by [Russian] aircraft," the report added.

The fatalities, it said, included four organizers of a terrorist attack that killed at least 19 Syrian government soldiers and wounded as many as 27 others on Thursday.

The terror attack targeted a bus carrying the forces near the Syrian capital of Damascus. According to the official Syrian Arab News Agency (SANA), the attack saw the terrorists detonating an explosive device that had been attached to the vehicle.

Daesh invaded Syria in 2014, unleashing a campaign of bloodshed and destruction against the country.

The terror outfit overran huge swathes of the Syrian territory during lightning advances.

Syria's allies, Russia and Iran, however, rushed to the country's support, respectively providing the Syrian military with aerial backup and military advisory assistance.

The combined effort helped Damascus reverse the Takfiris' gains until the outfit was eventually defeated in late 2017.

Daesh’s remnants, though, keep staging sporadic attacks throughout Syria, attempting to regroup and unleash fresh violence against the nation.