MEXICO CITY (AP) -- Mexican police are providing stepped-up security for a PepsiCo subsidiary targeted by firebomb attacks over the weekend, official said Tuesday. About one hundred state and federal police are guarding the distribution centers of Sabritas, a Mexican snack firm owned by PepsiCo, said Julio Hernandez, a spokesman for western Michoacan state. Hernandez said the attacks could further hurt investment in the state, considered the home turf of the Knights Templar drug cartel. Hernandez said it appears a drug gang was involved in the attacks that burned dozens of Sabritas delivery trucks and damaged buildings at five distribution centers in Michoacan and the neighboring state of Guanajuato. Guanajuato state attorney general Carlos Zamarripa said police there had detained four alleged members of the Knights Templar cartel in connection with the attacks. Zamarripa said one of the suspects suggested the company was attacked as part of an extortion scheme, but didn't know for sure. The suspects said they were simply ordered to burn Sabritas delivery trucks.