Escondida strike turns violent as protesters block roads, battle police

SANTIAGO, March 1 (Reuters) - The three-week-long strike at Chile (Stuttgart: 704599.SG - news) 's Escondida, the world's biggest copper mine, turned ugly on Wednesday when a group of protesters blocked a highway, provoking confrontations with the police.

Escondida's approximately 2,500 unionized workers began a strike on Feb. 9 after contract talks with mine owner BHP Billiton failed, boosting global copper prices on expectations of tighter supply.

Early Wednesday morning, dozens of protesters, some with shirts, caps and flags bearing the union's emblem, illegally barricaded the main road that connects the regional city of Antofagasta (Other OTC: ANFGF - news) with the mine.

A Reuters witness said they burned tyres and threw rocks and sticks at the police, who responded with tear gas. By late morning, the protesters had dispersed.

The union did not immediately respond to requests for comment.

The events reflect the increasing bitterness and division between the two sides, as the pressure to secure a deal on both ratchets up, but whose positions still appear to be far apart after three weeks of strike.

Key differences include disagreement over the level of benefits new workers should receive, and planned changes to shift patterns and benefits.

The union complained earlier this week that BHP had failed to make back payments to workers, while the company said that it would make the payments once the strike had ended, in accordance with Chilean law.

A local judge ruled that a deferred payment from 2016 should go out to workers within 48 hours, the union said late Tuesday. The union is keen to prevent workers from losing enthusiasm as the strike drags on, especially as after 30 days individual miners have the right to break from the union agreement and accept the company offer.

The company has waived the right to replace workers before 30 days, sacrificing output in an attempt to ease tensions and potentially weaken the union position.

A government-led attempt at mediation failed last week. Although both sides say they are open to talks, there has been little concrete sign of a resumption of dialogue in the near future.

(Reporting by Fabian Cambero,; Additional reporting by John Yevenes in Antofagasta; Writing by Rosalba O'Brien; Editing by Alistair Bell)