BANDA ACEH, Indonesia - U.N. Secretary-General Kofi Annan described the devastation on Indonesia's tsunami-battered Sumatra island today as the worst he's ever seen, while authorities there pulled 4,000 new bodies from the rubble, bringing the confirmed overall death toll to nearly 145,000.

Twelve days after the tsunami hit, Annan and World Bank President James Wolfensohn flew over the island's west coast and then drove to the shattered coastal town of Meulaboh, where families picked through piles of rubble six feet high.

"I have never seen such utter destruction mile after mile," a shaken Annan told reporters afterward. "You wonder where are the people? What has happened to them?"

With tens of thousands still missing and threatened by disease from the Dec. 26 earthquake and killer waves that hit 11 nations, the United Nations said the death toll would keep climbing.

"I think we have to be aware that very, very many of the victims have been swept away and many, many will not reappear," U.N. humanitarian chief Jan Egeland said in New York. "The 150,000 dead figure is a very low figure. It will be much bigger."

Hardest hit was Sumatra, which was closest to the 9.0 magnitude quake, and where officials today said they'd uncovered an additional 4,289 bodies - mostly in Meulaboh, which had been cut off by washed-out roads - raising Indonesia's toll to 98,489. Officials had briefly raised the toll to 113,306 today but scaled it back later, blaming the inaccuracy on poor radio links with remote officials.

Security concerns for foreign aid workers emerged. The South Korean government asked its aid workers, some of them affiliated with Christian groups, not to engage in religious activities that could provoke Islamic radicals.

Also, in an apparent sign that American relief agencies want to keep a lower profile, several trucks delivering aid for U.S AID removed large banners marking the shipments as American.

Annan's visit came after he attended a summit of world leaders in Jakarta on Thursday on how to turn one of history's largest-ever aid packages - nearly $4 billion in pledges - into food for the hungry and shelter for the homeless. The U.N. chief urged nations to come up immediately with their promised aid, and to break with past practices of pledging much and delivering little.

Secretary of State Colin Powell arrived in Sri Lanka, where more than 30,000 people died, to inspect tsunami-devastated areas in the south and hold talks on relief efforts.

"I had a chance to witness the destruction firsthand, and only by seeing it on the ground can you really appreciate what it must have been like on that terrible day," he said. "But I am impressed to see people cleaning up, helping their neighbors."

While some areas in Thailand remained scenes of total devastation, other Thai resorts were looking to the future. Cleanup on several beaches is almost complete and tour operators were eager to get back to business.

"It's amazing how fast things have gone back to normal. The Thais have done a brilliant job of organizing disaster efforts and getting things cleaned up," said Peter Elsey, 48, an English tourist who lives in Singapore and owns a house in Phuket.

Elsewhere in Thailand, though, officials said more than 500 migrant workers were being deported for looting tsunami-damaged buildings. Maj. Vachara Sangvorayothin said an "army of Burmese workers are on a stealing spree."

In Indonesia, some aid officials were reviewing their security precautions after the arrival of some 80 members of a radical Islamic group. The group, Laskar Mujahidin, accused of taking part in Muslim-Christian fighting in another part of Indonesia between 1999 and 2001, has set up a relief camp - but said it was only there to help.

"We are not here to fight, we've come to help. We've got no problem with the foreigners as long as they have no hidden agenda," said group leader Salman Alfarizi.

India's finance minister, meanwhile, said his country was open to accepting international aid, a departure from the country's long-held stance of refusing outside help.

Minister P. Chidambaram said India is fully capable of providing short-term emergency aid to its citizens but needs help with the more expensive reconstruction stage. Almost 10,000 people died from the floods in India.