Walmart de Mexico SAB is being investigated after local shoppers complained a store in Boca del Rio held a cockfight to promote a soda company.

The Walmex spokesman told Bloomberg it's all a misunderstanding because the roosters weren't armed with blades, there was no betting and the birds weren't harmed.

"It wasn't a cockfight," Antonio Ocaranza said. "There wasn't anything that would be in violation of any game regulations."

Customers posted photos on social media of the Sept. 15 promotion, which was staged by a local soda company.

Shame on you @Walmart celebrating Mexico's independence day with animal cruelty. Cockfight at Boca del Rio's store pic.twitter.com/ZtNrWDyt0q — Diego Cobo (@DCecol) September 16, 2014

Jose Luis Hernandez, the commercial director of the city of Boca del Rio, said the company could be fined about $8,000 if they are found guilty. Walmex, a subsidiary of Walmart, has until Sept. 24 to present evidence.

Cockfighting involves putting two roosters into a pit to have them fight, often to the death. Sometimes, blades are attached to the roosters' legs to inflict injuries and speed up matches.