WASHINGTON - US and allied forces carried out “large-scale” strikes against the Islamic State militant group in Syria on Jan 10, the US military said, in the latest response to an attack in December that left three Americans dead.

Washington said a lone gunman from the militant group carried out

the Dec 13 attack

in Palmyra - home to UNESCO-listed ancient ruins and once controlled by militant fighters - that killed two US soldiers and a US civilian interpreter.