Four people, including two children, died and 96 others were hospitalized Thursday for food poisoning in a town west of Guatemala’s capital.

The fire department said the victims ate fruit and vegetables that weren’t properly cleaned in the town of Santo Domingo Xenacoj. A doctor at one of the hospitals said the medical exams show the deaths were caused by E. coli bacteria.

Jose Morales, head doctor at the town’s health center, told The Associated Press that dozens of people had been treated there.

“We were able to identify the bacteria E. coli and these bacteria grew because of the poor hygiene in the food,” Morales said.

The strain of E. coli was not identified so it is difficult to know whether proper cleaning would have prevented or reduced the outbreak, or whether the contamination needed to be prevented further upstream.