With aid pledges for the devastating Indian Ocean tsunami already reaching between $3 billion and $4 billion, the United Nations health agency warned again today that 150,000 people are at "extreme risk" of dying from preventable diseases unless clean drinking water and other basic needs are restored within days.

Praising the enormous global outpouring of pledges for the victims of last week’s devastating tsunami in the Indian Ocean, United Nations Emergency Relief Coordinator Jan Egeland today delivered “a few messages” of thanks, caution and pleas for coordination.

In a bid to reduce the appalling toll of future tsunamis, the United Nations is moving ahead with efforts to set up early warning systems in the Indian Ocean, Caribbean and Mediterranean Seas similar to one that already exists for the volcano and earthquake-prone Pacific Rim region.

Rejecting myths arising out of major historical plagues, relief workers coping with large numbers of people killed by natural disasters such as last week’s earthquake and tsunami in South Asia should make every effort to respect the traditions of the affected communities and preserve the individual identities of the dead, the United Nations health agency says.