At least 38 Islamic State (IS) militants fighters have been killed in US-led coalition air strikes this week near Syria's ancient city of Palmyra, a monitor said on Saturday.
The Islamist militants retook Palmyra in central Syria on December 11, just eight months after the army backed by Russia drove them out.
On Thursday, US-led coalition aircraft destroyed heavy weaponry seized by the Islamist militants when they retook the city, the coalition said.
A statement on Friday said the strikes destroyed an air defence artillery system, 14 tanks, three artillery systems, two IS-held buildings and two tactical vehicles.
Among the Russian weaponry IS captured around Palmyra were thought to be modern surface-to-air missiles, or SAMs, giving Islamist militants the potential capability to shoot down aircraft, a coalition official told AFP.
The Syrian Observatory for Human Rights, a monitoring group based in Britain, said that "at least 38 IS members were killed in the air strikes".
The strikes, near the Tiyas military air base northeast of Palmyra, helped regime forces gain some ground west of the fabled city, said the Observatory.
Palmyra is a UNESCO World Heritage site, and its recapture by IS gave the Islamist militants a propaganda boost as they face assaults on two of their key strongholds -- Raqa in Syria and Iraq's second city Mosul.