The Garment Manufacturers Association in Cambodia (GMAC) said Thursday most of its 559 factories would continue to be closed due to security concerns after six pro-opposition trade unions led striking workers to destroy factories' properties and forced workers to join their protests.

"Because of the current unrest and danger in the garment sector, the GMAC has requested the Labor Ministry to suspend the productions in these factories indefinitely,"GMAC's Secretary General Ken Loo wrote in a request to Labor Minister Ith Samheng.

In another letter to Finance Minister Aun Porn Moniroth, Ken Loo asked the minister to allow factories to re-export garment materials and equipment to their production bases in other countries so that they could meet buyers' orders.

"Due to the strikes, all GMAC members have not been able to meet production schedules and cannot deliver products to buyers on schedule. In order to reduce a great loss of money, the factories have to transfer production orders to bases in other countries,"he wrote in the letter.

Cambodia has closed all garment and shoe factories since Wednesday last week after six pro-opposition trade unions led thousands of workers to go on strikes demanding the government to double the monthly minimum wage in the garment sector to 160 US dollars from the current 80 US dollars.

The government decided Tuesday to raise the minimum wage in the garment sector to 100 US dollars from the current 80 US dollars a month. However, the six pro-opposition trade unions rejected the offer and vowed to go on strikes.

The Southeast Asian nation has about 900 garment and shoe factories employing about 600,000 workers, according to Labor Ministry spokesman Heng Sour. The industry, the kingdom's largest foreign exchange earner, generated 5 billion US dollars in revenues a year.

On Thursday morning, about 500 factories have reopened and some 80 percent of the workers have returned to work, he said.

About 400 factories were still closed on security and safety concerns, he said, adding that striking workers were rallying in front of more than 30 factories to demand the government to double their minimum wages.

However, Ken Loo said those factories had been closed a few hour after re-operations since striking workers unlawfully entered factories to force workers to join their protests.

"The situation is getting worse because after the workers started working Thursday morning, gangsters in the striking unions had entered the factories to chase them out and destroyed factories' properties," he told Xinhua.

One of the garment strikes turned violent on Thursday morning. Around 100 security forces, armed with batons and shields, clashed with hundreds of striking workers at a Cambodian garment factory on the outskirts of Phnom Penh, leaving several protesters injured and 15 others arrested.

"Hundreds of protesting workers had tried to destroy the factory's property, so security forces had to take action against them," Kheng Tito, spokesman for the National Military Police, told Xinhua after a 20-minute clash at Yak Jing Garment Factory. " We could not allow them to cause anarchy and chaos."

He said 15 people, including Von Pov, president of the Independent Democratic Association of Informal Economy, and five Buddhist monks, were arrested for an inquiry after the incident.

Kheng Tito said those monks were fake.

"They are not workers, but they joined to incite striking garment workers to destroy the factory's property," he said. "They will be charged with triggering violence."

It was the second clash between security forces and protesters in one week. Last Friday, three anti-riot police officers and four striking workers were injured in a clash at the Phnom Penh Special Economic Zone.