John Hendra, outgoing chief of the UN's Vietnam mission, told reporters that around half the people from ethnic minorities existed at poverty levels.

"One in two ethnic minorities now are likely to find themselves in poverty," against one in 11 for the rest of the population as a whole, Hendra said.

A World Bank report in 2009 said Vietnam's 53 minority peoples, who are distinct from the majority Kinh, numbered nearly 10 million out of the 86-million-strong population.

Hendra said ethnic areas were among those with the "most persistent and stubborn" poverty, with access to health, maternal mortality rates and nutritional levels far worse then other parts of the country.

In early May, thousands of ethnic Hmong gathered in the northwestern province of Dien Bien, calling for greater autonomy and religious freedom and leading to minor clashes with Vietnamese soldiers, a military source told AFP.

Vietnam's foreign ministry said some people "abused" the information and campaigned for the establishment of a separate Hmong kingdom.

"It's one of the poorest areas in Vietnam and has a very high level of poverty," Hendra said, adding it is a challenge now to get "a clear view (of) what's exactly happening there".

The military source said special forces troops were among military reinforcements sent to the area, where soldiers were combing mountains for protest leaders.

But state-controlled media on Tuesday quoted Deputy Prime Minister Truong Vinh Trong as saying the incident had been settled peacefully and the gathering had dispersed.

In recent years the government has identified reducing ethnic poverty as a priority.

Agence France Presse - May 10, 2011