More than 350 people have died from cholera in Nigeria in the first nine months of this year, a 239 percent jump from the same period last year, data from the Nigeria Centre for Disease Control (NCDC) showed on Monday.

Cholera, a water-borne disease, is not uncommon in Nigeria where health authorities say there is a lack of potable drinking water in rural areas and urban slums.

NCDC said 359 people had died between January and September compared to 106 during the same period last year.

The number of suspected cholera cases also surged to 10,837, up from 3,387 the previous year, with most of those affected being children under five years old.

Lagos, the country’s commercial capital, recorded the highest number of cases, NCDC said.