A new front line has been emerging in Iraq, separating the semi-autonomous Kurdish region not just from the militants of the so-called Islamic State but also from the rest of the country.

The Kurds say the 1,000km trench is designed to repel suicide bombers but there are fears in Baghdad that it is the first step in the break-up of the country.

The BBC's Ahmed Maher travelled to Rabiaa, a town in the north-west, to see the trench.