With the confirmed death toll climbing to 10,204, and fears that the final total could be as high as 45,000, Mr Annan said Turkey would need help for many months to come.

Officials say the bodies of up to 35,000 people could still be trapped in the rubble of collapsed buildings.

The BBc's James Coomorasamy reports: "The immediate priority is to stop the spread of disease"

Meanwhile without proper water supplies or sanitation, and with thousands of bodies yet to be buried, fears are mounting that the summer heat could trigger epidemics of diseases such as cholera, typhoid and dysentery.

In an effort to keep the threat in check, rescue workers have been spraying worst-hit areas with disinfectant and distributing thousands of water purification tablets.

"We are all well aware of the magnitude of the devastation and suffering caused by this tragedy," Mr Annan said in a statement at UN headquarters in New York.

"The needs remain enormous both for initial relief and rehabilitation."

Mr Annan's Deputy Spokesman, Manoel de Almeida e Silva, said the UN was prepared to co-ordinate the international relief effort and was already working to produce lists of what was needed from donors.

Navy aid

The USS Kearsarge has gone to the disaster zone

Mr Annan's comments came as three US naval ships prepared to dock in Istanbul on Saturday to join the rescue and relief operation.

The USS Kearsarge - the largest US naval vessel in the area - and two supporting ships will provide 22 helicopters, cranes, bulldozers, jeeps and more than 2,000 American marines.

They also carry an impressive array of medical facilities including five x-ray units and six operating theatres.

Government response

The BBC's Alva McNicol reports on the first major supply of aid to be sent by the British government"

But aid agencies say much more aid is still needed and will be for many weeks to come.

The Turkish Government has been defending its handling of the disaster in the face of intense media criticism.

During a tour of the disaster area near Bolu, the Turkish President, Suleyman Demirel, denied that state resources had responded too slowly

(Click here to see a map of where the earthquake struck)

In Los Angeles, Muslims prayed for earthquake victims on the other side of the planet

"Of course, anyone suffering from this disaster asks the whereabouts of the state," the official Anatolia news agency quoted him as saying.

"But the state is...not a miraculous institution."

His comments were supported by Foreign Minister Ismail Cem who acknowledged some organisational problems, but said the sheer size of the quake had presented the authorities with an impossible task.

Prime Minister Bulent Ecevit said unfair criticism demoralised officials who were working day and night on the rescue effort despite losing members of their own families.

Contractors arrested

The government has promised to investigate widespread allegations that shoddy building work and lax enforcement of building regulations contributed to the high death toll.

Officials say large numbers of unburied bodies risk the spread of disease

Police were reported to have detained three building contractors in the city of Eskisehir on Friday.

Other reports said a construction executive in the town of Adapazari came under attack as angry residents tried to set his car on fire.

With temperatures continuing to rise, hopes are fading that rescue workers will find any more survivors.

However, most are refusing to give up hope and continuing to work almost non-stop to dig through tonnes of rubble.

On Friday, an Israeli team pulled an 11-year-old girl from the rubble of a collapsed building in Cinarcik, near the western city of Yalova, after she had been entombed for more than 80 hours.

Aftershocks continue

As efforts continue, hundreds of thousands of people have spent another night sleeping outdoors, either because made homeless or heeding official warnings of aftershocks.

Since the original quake at 0302 local time on Tuesday, there are reported to have been more than 1,300 aftershocks.

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