Cambodia's booming but strike-ridden garment industry was hit by fresh protests on Monday, as hundreds of workers took to the streets of the capital to protest over the dismissal of pro-union staff.

"We demand our friends back to work. They were not doing anything wrong," insisted 30-year-old Heng Vanna, who earns 40 dollars a month from the Chinese-owned Luen Thai Garments.

Scores of police were on hand to supervise the protest, eager to keep disgruntled staff out of the way of visiting Lao Prime Minister Sisavath Keobounphanh, who arrived earlier on Monday for a five-day official tour.

"Life is too hard," complained Deouk Saveth, 20, adding that the 350 protestors were also demanding a monthly bonus of just five dollars. "Our wage is not enough for rice and rent," she added, as the workers marched to parliament and then moved their protest to the United States embassy, before camping outside the labour ministry.

Officials from Luen Thai Garments Co Ltd were not available for comment.

The Cambodian government has been under pressure to drastically improve working conditions in the country's fast-growing industry following a refusal by the United States to increase quotas in Cambodia's favour. The US has demanded "concrete improvements" in labour conditions, but International Labour Organisation inspectors admit little progress has been made in either working environments or salaries.

The garment industry accounts for the employment of over 100,000 people - mostly young women - and officials estimate earnings in 1999 totalled about 600 million US dollars. The US accounted for 70 per cent of exports.

However the sector, much of which is owned by Chinese companies, remains dogged by almost monthly strikes amid unresolved complaints over what unions complain are Dickensian working conditions and low pay. Low labour costs have attracted scores of western clothing manufacturers, including fashion retailer Gap, Italian sports label Lotto and cigarette spin-off Camel Trophy to contract out production here.

In a separate development, interior ministry officials announced the arrest of 10 businessmen accused of cheating the quota process by forging costly quota allocation certificates in a bid to bypass tax and strict controls. The 10 men included two Chinese and one Australian, deputy director of criminal police Heng Pov told reporters, adding that the fraud was estimated to have cost the government millions of dollars.

The quotas imposed by the US on Cambodia remain a major grievence for both manufacturers and the government, with officials claiming foreign factories are "stealing" Cambodia's quota by falsely marking products as "Made in Cambodia."