Winds toppled hundreds of power lines, signposts and trees as the storm moved northward fast early Monday, the National Emergency Management Agency (NEMA) said.

Power was cut to 320,000 houses in south-western provinces, while roads, port facilities and breakwaters were destroyed in dozens of places, it said.

"We have no nationwide tallies right now but property damage is expected to rise sharply," a NEMA official told AFP. Thousands of boats were staying in port along the west coast.

Weathermen said Muifa was some 250 kilometres west of Incheon around midday.

The southern resort island of Jeju was among areas hardest hit, with some places on the island drenched by up to 601 millimetres \of rain Sunday and Monday. Many flights were cancelled.

A 76-year-old fisherman was found dead Sunday on the southern island of Wando. A man in his 40s drowned after being swept away by stormy seas in the southern port of Busan.

A 50-year-old woman was found dead Monday after falling into a flooded stream in Hwasun in the southwest. A 65-year-old man was reported missing in Busan.

South and North Korea are still clearing up after record rain battered the peninsula late last month, leaving at least 59 people dead in the South.

State media in the North has said floods killed 30 people, destroyed more than 6,750 houses and inundated more than 48,000 hectares of farmland.

Copyright AFP (Agence France-Presse), 2011