South Korean President Kim Dae-jung has responded to mounting criticism by reshuffling his cabinet, sacking seven ministers and bringing in the country's first woman prime minister.

The move comes less than two weeks after a naval battle with North Korea left four South Korean sailors dead, prompting calls for the defence minister to resign.

Kim Dae-jung is under attack for corruption charges against his sons

President Kim, who has seen his authority damaged by corruption scandals involving two of his three sons, was also trying to shore up his ruling Millennium Democratic Party (MDP) ahead of important by-elections next month and a presidential poll in December.

President Kim's five-year term ends next February, and he is constitutionally barred from standing for re-election.

The new prime minister, Chang Sang, 62, is a university administrator rather than a career politician. She holds a doctorate in philosophy from Princeton University in the United States.

She has been president of Ewha Women's University since 1996, and a consultant on Korean reunification. Her appointment must now be ratified by the National Assembly.

The role of women is very important in the 21st century

Presidential chief of staff Park Jie-won

As prime minister she holds the second highest executive office, a significant departure for a traditionally male-dominated society.

"The role of women is very important in the 21st century," said presidential chief of staff Park Jie-won.

Other new ministers have taken over the defence, culture, health, information, tourism and justice portfolios.

But three important ministers - in charge of foreign relations, economics and dealings with North Korea - remained in place.

The opposition Grand National Party described the reshuffle as a "great disappointment".

Minister under attack

Outgoing Defence Minister Kim Dong-shin had been criticised for the ministry's slow reaction to the naval incident on 29 June.

Out: Former Defence Minister Kim Dong-shin

The shooting began when two South Korean navy patrol vessels tried to drive two North Korean warships out of South Korean-controlled waters in the Yellow Sea.

Apart from the four South Korean dead, 19 sailors were injured and one listed as missing.

South Korea blamed the North for staging a "premeditated" incident, while North Korea said that South Korean vessels fired first.

An estimated 30 North Korean sailors died in the clash.

The North raised tensions on Wednesday, when it accused the South of again sailing in to its territorial waters.

New Defence Minister Lee Jun, 62, is a retired four-star general who once commanded the South's largest field army.

He is also an MDP official.