HARARE, Zimbabwe — The death toll from Zimbabwe's cholera outbreak has risen sharply, the United Nations said today, reporting 746 deaths and 15,572 cases of the water-borne disease.

Cholera has spread in Zimbabwe because of the country's crumbling health care system and water infrastructure. Last week, Zimbabwe declared a health emergency because of cholera and the collapse of its health services.

The U.N. humanitarian office in Geneva reported Tuesday that 589 people had died out of 13,960 cases.

Information Minister Sikhanyiso Ndlovu claimed the disease was "under control."

However, aid agencies have warned about coming rains further spreading cholera.