In the southern Iraqi town of al-Shatrah, after canal-side cafes have shed the last of their customers and demonstrators occupying the central market square have dispersed to their homes, an eerie howl from a brass trumpet breaks the uneasy silence.
This is the signal for a group of young men to re-congregate for a night of personal and targeted action: burning the homes of local officials, politicians and militia leaders.
On a bridge over the Gharraf Canal, between outbreaks of chanting, the protesters debate about whose house to target. With the internet cut off, and heavily armed riot police roaming the streets, the young demonstrators here have turned to trumpet calls, an old and trusted way to communicate and organise battle campaigns.
Positioned at different corners in the town’s market, the trumpets – some old brass ones used in weddings and religious festivals, others brightly coloured plastic vuvuzelas – have their own code. A long sound means gather, a staccato burst means disperse.