SANTIAGO, May 10, 2010 (Dow Jones Commodities News via Comtex) -- Copper mining operations at Chile's Collahuasi mine remain "restricted" due to a contract workers strike, a company spokeswoman said Monday.

On Friday, several thousand contract workers from various mining services providers went on strike, barricading the main access to the mining compound.

Collahuasi, one of the largest copper mines in northern Chile, is located at about 4,500 meters above sea level in the Andes mountains.

The contract workers demand improved working conditions in line with the accommodations and benefits that Collahuasi staff workers receive, and are asking for a 1 million peso end-of-conflict payment ($1,898) to end their strike.

Staff workers, meanwhile, haven't been able to leave the mining compound and some fear for their safety, especially in light of the high altitude at which the mine is located, union leader Juan Barraza told Dow Jones Newswires.

The mining company is calling on striking workers to end their walkout and allow staff workers to freely move in and out of the mining compound.

"We call for rationality so as to allow our people to freely circulate, as per their request, as they're being held against their will and without enough food," Collahuasi said in a statement late Sunday.

Collahuasi produces about 500,000 tons of copper a year, or about 10% of Chile's output.

Diversified mining companies Xstrata PLC (XTA.LN) and Anglo American PLC (AAL.LN, AAUKY) each own a 44% stake in the mine, with the rest held by a consortium led by Mitsui & Co. (MITSY, 8031.TO).