A demonstrator hurls a tear gas canister back towards police lines in Fergusson, Missouri, after an apparent peaceful demonstration was broken up by heavily armed police officers overnight.
Police chief Thomas Jackson, who has been the public face of the city torn by the death on Saturday of Michael Brown, 18, said earlier that the St Louis County investigation of the shooting could take weeks to complete.
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Ms Ardern posted a photo showing her and Clarke Gayford with the baby at Auckland City Hospital.
Nasa says scientists have found 95% of near-Earth objects measuring a kilometre or bigger, but the remaining 5% could inflict big damage.
There will be showers during the morning across Scotland, but these will clear during the afternoon.