"Today marks the 20th anniversary of the worst nuclear power plant accident in history," Annan's spokesman Stephane Dujarric said in a statement.

He noted that many hard lessons had been learned from the disaster, including the importance of providing the public with transparent, timely and credible information.

"The Secretary General believes that the best way for the international community to pay homage to those who suffered from Chernobyl is to provide generous support to programmes designed to help traumatized communities regain self-sufficiency, and affected families resume normal, healthy lives," the statement said.

The United Nations has said that between 4,000 and 9,000 people can be expected to die as a direct result of the accident. Environmental groups put the figure at 100,000 and higher.

Some five million people continue to live in areas affected by the accident in Belarus, Ukraine and Russia, the three countries worst hit by the disaster.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.