Shots were fired and police shouted through bullhorns for protesters to disperse, witnesses said, as chaos erupted in Ferguson, Missouri, which has been racked by protests since an unarmed black teenager was shot by police last week.
Hundreds of protesters fled to safety after authorities fired canisters of smoke to disperse them hours ahead of a planned midnight curfew.
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The mum wrote the emotional letter after her eight-year-old with Down's syndrome was the only child in his class not invited to a party.
More than 1,800 litter pickers will clear an estimated 57 tonnes of reusable items and half a million sacks of rubbish.
Time for Project Let's-Make-the-Best-of-it.