Islamic State militants have set up giant television screens in the Iraqi city of Ramadi and are using them to proclaim that they will seize more Iraqi territory after capturing the provincial capital last month, residents said.

Efforts by the Sh'ite Muslim-led government and its American allies to break the hardline group's control of about a third of Iraq are currently focused on Ramadi, in Sunni Muslim heartland Anbar province.

"They have started to show videos of their military operations in Iraq and also show confessions by captured soldiers," said the owner of a small food shop near one of the screens in central Ramadi.