Striking workers at the world's biggest copper mine in Chile have rejected the latest offer from employers, bringing the strike into its third week.

Employees at the Escondida mine in northern Chile turned down the offer from majority owner BHP Billiton, an Australian firm, after a meeting late Sunday.

The company offered the mine's 2,000 employees a three-year deal or a four-year deal. The three-year deal included a four percent raise and almost $24,000 in bonuses, while the second deal included an additional raise of 1.3 percent in the fourth year and a $32,000 bonus.

But employees say the offers aren't enough. They say they want a deal that reflects the surge in copper prices over the past several years.

Copper prices were near $3.40 a pound on Friday.

The strike began August 7.

Production at the mine has been at about 50 percent since the strike began. On Friday, BHP Billiton shut down the mine altogether after striking workers blocked the mine's access roads.

Miners initially demanded a 13 percent wage increase and a $30,000 bonus, but cut their demands last week to 10 percent.

The Escondida copper mine is in Chile's Atacama desert north of the capital of Santiago. The mine accounts for eight percent of world copper production, and 20 percent of copper production in Chile.

Some information for this report was provided by Reuters.