Civil protection authorities have confirmed new toxic spills in northwestern Mexico, where a massive acid spill from a copper mine contaminated waterways.

Sonora's civil protection union said it "implemented protocols to protect the surrounding Sonora River population, after confirmed reports of toxic spills from the Buenavista del Cobre mine," a subsidiary of Grupo Mexico.

Environmental protection agency PROFEPA said late Sunday that the spills were triggered by heavy rains from Hurricane Odile, stressing that the level of contamination was not a health hazard.

During an overflight of the mine, civil protection authorities observed the spill spreading to tributaries leading to the Bacanuchi River.

The Buenavista copper mine is one of the biggest in the world, with annual production of 200,000 tonnes.

On August 6, a leak in a container caused an environmental catastrophe that spilled 40,000 cubic meters of sulfuric acid in the Tinajas stream, located in the town of Cananea, which connects the Bacanuchi River to the Sonora River.

The spill contaminated water reaching seven towns, affecting a total of about 20,000 inhabitants.

On Friday, the Sonora government announced a break with the company, saying mining executives have hampered investigations.

Grupo Mexico has set side $147 million to pay for damages. It has also been fined $3 million.

Lawmakers have also called for scrapping the concession to Grupo Mexico after what is considered the worst environmental disaster in recent times for the country's mining industry.

The federal government has ruled out any suspension of the company's rights to use the mine.