Tonga has begun moves to expel many of its Chinese residents after a wave of ethnic violence against them.

Police in Nuku'alofa say there have been about 100 cases of Tongans assaulting Chinese, in some cases burning shops.

The tiny kingdom's chief immigration officer, Susana Fotu, said more than 600 Chinese storekeepers and their families would be given a year to leave when their work permits expired.

The Government was acting with "Polynesian courtesy" in giving them time to get their affairs in order. The policy had yet to be made public but was on the initiative of the Prime Min-ister, Prince 'Ulakalala Lavaka Ata, youngest child of King Taufa'ahau Tupou IV.

The ailing 83-year-old King called this month for thousands more Chinese to be welcomed to Tonga, but Ms Fotu said his son was responding to widespread anger at the growing presence of the storekeepers and to fear that they would dominate the economy.

It is understood the King has not been told about the crackdown on the Chinese.

He told a Herald correspondent that Tongans could learn from the virtues of hard work and saving practised by Chinese.

"Only lazy Tongans don't want the Chinese here - hard-working Tongans welcome them."

But other members of the royal family feel under mounting pressure to take drastic action against the newcomers, and the Chinese Embassy in Tonga admits to being concerned about the violence towards its nationals.

Resentment is fuelled by unemployment well into double figures. Only about a quarter of the 2000 young people who leave school each year are able to find jobs without moving to New Zealand or elsewhere.

The main influx of Chinese began in the mid-1990s on work permits promoted by the royal family.

Auckland-based Tongan pro-democracy lawyer Nalesoni Tupou said last night that hardly a day went by without a case of ethnic violence coming before the kingdom's courts.

He was due back there next year to defend three young Tongans accused of kidnapping and assaulting Chinese shopkeepers.