A rock and a ball were allegedly thrown at Prime Minister John Key's limousine in the Napier suburb of Maraenui yesterday.
Police arrested a 22-year-old man and charged him with disorderly behaviour.
Mr Key was forced to stand by as children chanted anti-Government slogans to his face and an egg was thrown at his car.
He said they were idle, mindless acts: "These kids were about 10 or 12 and were saying things they didn't understand. It's the school holidays so I suppose it is something to do."
Mr Key's visit to a Housing New Zealand redevelopment was greeted by 10 adult protesters with about 25 children in support chanting: "One, two, three, four, stop the war on the poor," and "Maraenui under attack, stand up, fight back".