Three Hong Kong children have jailed for more than three years for the armed hold-up of a jewellery shop, a newspaper said on Thursday, with the court saying the stiff sentence was in the public interest.

Disguised with masks and caps, the two boys and one girl, all aged 14, threatened staff at the shop with knives in September last year, grabbing gold necklaces, bracelets and pendants valued at more than HK$1 million (64,176 pounds).

Sentencing the three, now aged 15, the judge said the offence was too serious to warrant a training centre term despite the age of the three, the South China Morning Post said.

One boy, an apprentice to the mastermind goldsmith who had earlier been jailed for seven years, was sentenced to three years and seven months, while the other two, who are cousins, were jailed for three years and five months.

Earlier this week, a court heard that a nine-year-old Hong Kong girl travelled alone into mainland China to collect heroin and bring it back in her rucksack for a drug trafficker who paid her HK$1,200.