Fierce fighting in battle for Falluja, Iraq

The UN has said it is very concerned about the fate of some 50,000 civilians in Falluja, where Iraqi forces are battling so-called Islamic State.

Soldiers, police and militiamen began an offensive to retake the city, 50km (30 miles) west of Baghdad, on Monday.

The BBC's Jim Muir has been to the front line with Iraqi government forces.