SANTIAGO, Dominican Republic – At least 300 people have been hospitalized in the past few days with cholera symptoms in the city of Tamboril and Santiago, a province in the northern Dominican Republic, health officials said.

The outbreak of diarrhea may have been caused by the poor quality of drinking water consumed by residents, Santiago province public health director Ramon Martinez Henriquez said.

The majority of patients experienced diarrhea, while others also suffered from vomiting and abdominal pain.

The cases cannot be certified as cholera even though health officials are looking at the possibility, Martinez Henriquez said.

Many of the patients have been tested and samples sent to laboratories for analysis, Tamboril Public Hospital epidemiologist Dr. Felix Ramon Martinez said.

Tests on some of the samples indicate that the patients were suffering from bacterial infections, such as salmonellosis, parasitosis and other illnesses, but health officials have not ruled out the possibility that other patients may test positive for cholera, Martinez said.

The diarrhea cases were caused by drinking contaminated water, Martinez said.

A diarrhea outbreak in mid-June killed at least nine people in the Dominican Republic, but public health officials were only able to confirm that four of the deaths were caused by cholera.

A total of 315 people were treated for diarrhea in Tamboril and Santiago during the wave of illness earlier this summer.