MOSCOW -- The Russian military has scoffed at a top U.S. general’s suggestion that military equipment seized by the Islamic State of Iraq and Syria (ISIS) in the Syrian city of Palmyra could pose a threat to the U.S.-led coalition.

Russian Defense Ministry spokesman Maj. Gen. Igor Konashenkov said Thursday that an “insignificant number” of firearms and a few broken pieces of military hardware left in Palmyra “pose no threat to the international coalition.”

U.S. Lt. Gen. Stephen Townsend had said that ISIS got hold of weapons, possibly including air defense equipment, when they retook Palmyra from Syrian government troops earlier this week.

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A U.S. Defense official told CBS Radio News correspondent Cami McCormick on Thursday, however, that the Pentagon now believes ISIS did seize multiple rocket launchers and three SA-3C surface-to-air missile batteries, with four missiles each. The weapons are Soviet-era, according to the official, and ISIS likely doesn’t have the technical capacity to operate them, but they could in theory present a threat to aviation.

ISIS militants are believed to possess operational knowledge of the rocket launchers, but those pose significantly less of a threat to aircraft.

For the time being, however, it seemed the Pentagon was to wait and give the Russians and their Syrian partners the chance to destroy or otherwise bring the weapons under control.

“I think Russia will probably take action,” Townsend said Wednesday, adding that, “if they don’t, we will do what we need to do to defend ourselves” in coordination with the Russian forces. “I think maybe, probably, we will strike it if we see it moving away from Palmyra. I think if it stays -- as long as it stays in Palmyra, the Russians will have lead and the regime will have the lead to deal with that.”

The location of the missile batteries continued to be the focus of U.S. attention on Thursday, according to the defense official who told McCormick, “Those are the ones we’re watching very carefully. If we see any attempt to move them, they’re gone.”

U.S. defense officials told CBS News that the U.S. used a special phoneline established with Moscow -- ostensibly for puposes of “deconfliction” -- to inform the Russians that ISIS was in possession of the SA-3C systems.

While Konashenkov did not further address the issue of the weapons seized by ISIS in Palmyra, the Defense Ministry did say separately that the situation in Palmyra had been “stabilized” by the Syrian military operating with the support of Russian air power.

The city, a UNESCO World Heritage Site that was heavily damaged by ISIS militants while they held it the first time around, was recaptured last week by ISIS.