MEXICO CITY -- Extortion gangs have grown so bold in the Mexican city of Celaya that when local tortilla shop owners protested the problem at city hall, gunmen immediately attacked one of their businesses, killing three employees.
While gangs have demanded protection money in other parts of Mexico, seldom has retaliation for a public protest been so swift and deadly, and industry officials say tortilla shops have already started closing in the city of about 500,000 people.
On Tuesday, Celaya city officials pledged 150 more state police would be stationed in the city. The mayor said a special unit would investigate the killings.
The conflict became public on Monday when tortilla shop owners held a protest at city hall, saying gangs were demanding "amounts that are impossible to pay." Hours later, unidentified assailants killed the three employees of a tortilla shop and reportedly shot up another.
The prosecutors' office in the north-central state of Guanajuato did not respond to requests for comment on whether the killings were retaliation.
The Celaya Tortilla Industry association said in a statement that "many colleagues have opted to close" in the face of constant demands for protection money.
Guanajuato was once a relatively quiet industrial and farming state, but in recent years violent gangs have formed, deriving much of their income from drilling taps into government pipelines and stealing fuel. Following a government crackdown on pipeline thefts this year, there is speculation the gangs have turned to other illegal activities for income.
The association said drug stores have lost about $750,000 in sales in the last month because their supply trucks cannot enter large parts of the "tierra caliente" or "hot lands" in Michoacan and Guerrero states. It said they have lost another $1 million in that time period in freight shipment robberies.