HANOI (AFP)--A plan to let a Chinese company build a bauxite mine in Vietnam has triggered rare public outcry from critics, who say the environmental and social damage would far outweigh any economic benefit.

Some even fear the plan, agreed to by leaders of the two communist countries without broader dialogue, could ultimately mean the de facto seizure by Beijing of a strategic region of Vietnam.

Vietnam's government estimates the country's bauxite reserves at 5.5 billion tons - a major draw for the world's mining giants.

In 2007 it approved a plan for two major mining operations to be run by state-owned Vietnam National Coal, or Vinacomin, and Mineral Industries Group in the Central Highlands.

A subsidiary of Aluminum Corp. of China, or Chinalco, has been granted a contract to build one mine, while the U.S. aluminum company Alcoa Inc. (AA) has partnered with Vinacomin to explore the feasibility of a second.

But in a country that bitterly recalls 1,000 years of Chinese occupation - and more recently a brief 1979 border war - any presence of Vietnam's big neighbor on its territory is perceived by some as a menace.

Nguyen Ngoc, a writer whose work focuses on the Central Highlands and its people, said there was a longer-term risk of seeing the region come under strong Chinese influence.

"The Central Highlands constitute a strategic position for all of the south of Indochina," said Ngoc, who alleges Chinese companies are already exploiting bauxite across the border in Laos.

"They say that who is master of the Central Highlands is master of southern Indochina."

While the bauxite project presents "financial, ecological and social problems," he said the most important question was that of security and independence.

In a one-party state where public protest is rare, scientists, intellectuals and former soldiers have joined critics of the regime to denounce the government's plans.

"China has been notorious in the modern world as a country causing the biggest pollution as well as other problems," 135 Vietnamese intellectuals said in a petition criticizing the mining plan and delivered Friday to the National Assembly, or parliament.

Deputy Prime Minister Hoang Trung Hai has said the bauxite mining industry would help spur socio-economic development in the Central Highlands, the state Vietnam News Agency reported.

The government estimates the projects would require total investment of more than $10 billion and would, by 2025, annually produce between 13 million and 18 million tons of alumina, a partially-processed product of bauxite.

However, critics say the mines would bring only limited financial benefit to Vietnam, which plans to export most of the alumina.

The plan's most prominent opponent is Gen. Vo Nguyen Giap, 97, who led Vietnam's victory over French colonial forces.

In open letters to the government, he warned of the danger to the environment, to the lives of ethnic minorities, and to Vietnam's "security and defense."

The Ho Chi Minh City War Veterans' Association has expressed similar views, and economics professor Nguyen Quang Thai said in a recent report to the government that Giap's warning should be respected.

"We should not allow foreign laborers" into the area," Thai wrote, without naming China.

Exploitation of natural resources - notably for coffee production - has already provoked violent clashes in the Central Highlands, home to the ethnic minority Christian Montagnards, who have battled land confiscation and religious persecution.

Dissident monk Thich Quang Do, head of the banned Unified Buddhist Church of Vietnam, has urged people to denounce the "destructive effects" of the planned mine on indigenous people.

A permanent Chinese presence in the Central Highlands would pose "an alarming threat" to national security, he said.

If the bauxite projects are carried out, scientists fear massive destruction of the fertile soil where forests, coffee and tea grow.

They also worry about water pollution, and say the local population - some of whom received or will receive compensation - risk loss of land and aren't qualified to work in the facilities.

Writer Ngoc said there could be "new revolts" by the region's ethnic minorities.

Experts estimate thousands of Chinese would arrive for the bauxite projects, and say several hundred are already in Lam Dong province, where the ground is being cleared.

"For countries like Vietnam...exploiting natural resources for development is necessary," said geologist Dang Trung Thuan.

"Exploitation is obvious, but to what extent?"