At least 38 Islamic State group 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 jihadists 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 jihadists 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 jihadists 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 jihadists a propaganda boost as they face assaults on two of their key strongholds -- Raqa in Syria and Iraq's second city Mosul.

Coalition strike destroys IS-captured weapons near Palmyra
Washington (AFP) Dec 16, 2016 - US-led coalition aircraft have destroyed heavy weaponry seized by Islamic State jihadists when they retook the Syrian city of Palmyra from regime forces over the weekend, officials said Friday.

The strikes on Thursday destroyed an air defense artillery system, 14 tanks, three artillery systems, two IS-held buildings and two tactical vehicles, the coalition said in a statement.

Among the Russian weaponry the IS group captured around Palmyra were thought to be modern surface-to-air missiles, or SAMs, giving jihadists the potential capability to shoot down coalition jets, a coalition official told AFP.

Earlier on Wednesday, the commander of the coalition forces conducting air strikes against the IS group in Iraq and Syria, Lieutenant General Stephen Townsend, had said that "anything they (IS) seize poses a threat to the coalition, but we can manage those threats and we will."

Thursday's attack took place near the Tiyas military airfield near Palmyra, northeast of the fabled city along a highway.

The IS group overran Palmyra on Sunday, nine months after its fighters were expelled by Russian air strikes and forces loyal to President Bashar Al-Assad.

The jihadists had initially seized Palmyra in May 2015 and went on to blow up UNESCO-listed Roman-era temples and loot ancient relics.

Before the IS group retook the city, it had been the focus of Russian and Syrian counter-Islamic State operations and not an area were the US coalition was particularly active.

The White House has been withering in its criticism of Russia for losing control of the desert town, accusing Moscow of focusing more on helping the Assad regime retake Aleppo than its claim of fighting the Islamic State group -- also known as ISIL.

"(Russia) has only had one operational gain on the ground inside of Syria against ISIL. It has had that -- that gain rolled back," White House spokesman Josh Earnest said.

"In fact, the threat that is posed by ISIL is now worse because of Russia's failed strategy inside of Syria, because ISIL didn't just retake Palmyra, they retook Palmyra and all of the military equipment that the Assad regime, backed by Russia, had moved in there."

Despite the rhetorical clashes and arguments over Syria, the United States and Russia have established military back channels to ensure operations outside their usual zones of interest do not result in direct confrontation.