North Korea has also been hard hit by the typhoon and has delayed Red Cross talks with the South on family reunion visits for several days as a result.

The North's official KCNA agency said the typhoon has caused the deaths of "scores" of people in the North and has destroyed basic infrastructure over a wide area.

The death toll in the South is expected to rise further as searches for the missing continue, Kim Jin-young, a director at the National Disaster Prevention Headquarters, has warned.

Hampered by thick fog, troops have joined the search for survivors in South Korea, using electronic sensors to search for people buried deep in the mud.

Rescue workers are also attempting to provide evacuees with food and water. At least 16,000 people in remote villages have been cut off by landslides that buried and buckled roads, the National Disaster Prevention Headquarters said.

The government has designated four cities as disaster zones which means that their residents will qualify for financial help.

A farmer in the central village of Sangju was detained after he tried to set fire to an official building to protest against slow aid for farmers who lost crops just before harvest.

But agriculture ministry officials said that while vegetables and fallen fruit were ruined, the main harvest would not necessarily be affected, arguing that flooded rice fields were being drained quickly.

Unprecedented damage

Officials are warning that the damage is likely to be the worst in the nation's history - estimated at 1.05 trillion won ($880 million) and rising.

The southern city of Busan faces the additional problems of having to clear up before the Asian Games, due to begin at the end of September.

Several sports facilities, including part of a field hockey stadium, were severely damaged, the Associated Press news agency reported.

Rusa, the Malaysian word for deer, is the most powerful storm to hit the Korean peninsula since Typhoon Sarah in 1959, which left more than 840 dead or missing.