Chile declared a health alert Tuesday at a site where 500,000 pigs, abandoned by a slaughtering company, are said to be dying in large numbers due to a lack of food and water.
Health Minister Jaime Manalich visited the plant in Freirina, 800 kilometers (500 miles) north of Santiago in the Atacama region, and said that without food, water, cleaning or care the pigs had started to die.
The incident began when Freirina residents, angry about foul odor from the swine, held a protest march Thursday that culminated in riots. Demonstrators set two police cars on fire, and police arrested 23 protesters.
The angry locals closed access roads to the pig slaughtering site, and employees fled the plant.
"Because of the road closures from Thursday onward the animals have stopped receiving food, there is no sanitation, their waste is not being disposed of and we understand there is high mortality among the animals, particularly the young piglets," said Manalich.
The authorities declared a sanitary alert in the area and temporarily closed the plant, owned by the firm Agrosuper.
Plant officials acknowledged problems in the slaughtering plant ventilation system that increased the foul odors.
Fernando Flores, the Atacama governor, said steps were being taken to reverse the road closures and feed the pigs.