GENEVA: Millions of people will be at risk of disease unless there is immediate action to provide clean water in communities hit by tidal waves in South Asia, the UN Children's Fund (UNICEF) warned earlier this week.

"Millions of people will be at grave risk of waterborne disease," UNICEF said in a statement as the largest international aid operation rolled into the devastated coastal areas of the Indian Ocean.

On Tuesday, the World Health Organization (WHO) warned that diarrhoeal diseases, or mosquito borne dengue fever or malaria, could kill as many people as the tidal waves in South Asia.

"Standing water can be just as deadly," UNICEF executive director Carol Bellamy said on Wednesday. "This is definitely a case of water, water everywhere, and not a drop to drink'," Bellamy said.

"The floods have contaminated the water systems, leaving people with little choice but to use unclean surface water." "Under these conditions people will be hard put to protect themselves from cholera, diarrhoea and other deadly diseases," she added.

UNICEF said that children, who make up one third of the population in the worst affected countries, were particularly vulnerable. "Hundreds of thousands of children who survived the massive waves that destroyed their communities now risk getting seriously ill from something as simple as taking a drink of water," Bellamy said.

Bellamy said she did not know how many people could fall ill because of bad water or sanitary conditions. "But without doubt we know people will fall to disease. That's why it is essential that the relief campaign be focused on providing safe water right now," she added.

UNICEF said it had delivered water purification tablets in Sri Lanka, while more than 60 tons of supplies including sanitation equipment were also being flown to the island.

Water tanks and purification tablets were also being delivered in southern India. Other agencies, including the Red Cross, have been taking action to ensure clean water supplies and proper sanitation in the region. -AFP