A Chinese-run sugar refinery in Madagascar damaged last week during a violent labour dispute will seek compensation from the government of the island nation, a spokesman said Monday.

The damage is so severe that it may take three years to return production to normal levels, Sucoma spokesman Zhou Jianping said.

Four people were killed last week during riots in which sugar stocks were also looted.

The Chinese embassy in Madagascar at the weekend expressed shock at the violence and complained that Malagasy authorities had failed in their duty to protect the factory situated in the western part of the country.

"We will seek compensation," Zhou told a news conference in the capital, estimating the value of the damage at over one billion ariary ($389,000 or 313,000 euros).

"To fix this company, it will take perhaps three years."

He said the company would consider "rehabilitation" of the factory -- but only "if the government can provide us with a sustainable and peaceful investment environment".

Clashes between police and protesting Sucoma workers, who were demanding the release of two of their arrested leaders, turned deadly on Wednesday when two people were killed and nine wounded.

A policeman and a soldier posted to the factory were slashed to death with knives the next day.

By Monday, calm had returned to the factory in Morondava, where the homes of 20 Chinese managers had been ransacked and company property was destroyed.

Sucoma employs 2,000 workers, of which 700 are permanent staffers.

The Malagasy employees have been demanding contracts for the seasonal workers and better wages.

China's vast investment in Africa has led to social unease in some countries, with the visitors sometimes accused of exploiting workers.

Leon Clement, a workers' representative at Sucoma, said: "We don't want the Chinese, we do not want to work with the Chinese."

He said that "before government ministers they promise to give us more rights, but they never do".