(CNN) Russian and Syrian regime pilots bombed Syrian villages that "they thought were held by ISIS" -- but were in fact occupied by US-backed coalition forces, a US general said Wednesday.

Lt. Gen. Stephen Townsend, the top US commander in the fight against ISIS in Syria and Iraq, said ISIS fighters had withdrawn from the towns and Syrian-Arab coalition troops had moved in.

US forces serving in an advisory role witnessed the Russian and Syrian airstrikes, Townsend said.

Quick calls to Russian forces through "deconfliction channels" stopped the bombing, he said.

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