Workers block access to Codelco's Chuquicamata mine

A group of workers blocked road access to Chilean state copper producer Codelco's Chuquicamata mine (pictured) in northern Antofagasta region (II), in what the unions said was a warning strike.

The blockade began at 5am Wednesday and was lifted four hours later.

Union representatives said the protest was a response to the failure by Codelco to meet some aspects of their collective contract agreement.

The workers said the company has failed to fill some vacancies, curtailing workers' career paths, according to similar statements from unions No. 1 and 3.

In a release, Codelco claimed it has met all the conditions of the existing collective contract. The company added that it is in the process of adjusting the number of workers in each area to meet real requirements, and as a result, some positions are no longer required.

Hilario Ramírez, president of union No. 1, did not rule out the possibility of a strike at the more than a century-old mine, local press reported.

Chuquicamata produced 302,000t last year, compared to 309,000t in 2015. The company signed a new collective contract with Chuquicamata unions in December.