More than 200 civilians are reported to have been killed in a single US-led coalition raid on Mosul, as the United Nations warns the worst was yet to come for those still trapped in the Iraqi city.

Some 230 bodies of mostly women and children were pulled from three adjoining houses in the Jadida neighbourhood of west Mosul overnight Wednesday and into Thursday morning, according to witnesses.

Islamic State of Iraq and the Levant (Isil) had taken over the buildings to use as sniper positions and had been holding civilians there which they had rounded up to use as human shields.

A Mosul resident who has been documenting life under Isil and now the battle for the city under the name MosulEye told the Telegraph one of the trapped residents called him yesterday pleading for help, saying they had been without food and water for four days.