S Korean strikes often turn violent

State prosecutors also warned that they may target the organisers of industrial action that has brought the country's second-biggest oil refiner to a halt.

The disputes over pay and conditions have been declared illegal and come amid signs the economy is sputtering.

The government, meanwhile, has been criticised for not being tough enough.

In focus

President Roh Moo-hyun's actions will be closely watched by both investors and industrialists, many of whom have blamed stubborn and intransigent trade unions for many of the country's economic ills.

The Bank of Korea has said that labour problems were a key obstacle to boosting business investment.

The subway and refinery dispute follows industrial action at a string of firms in key sectors, including Hyundai Motors, Kia Motors and KorAm Bank.

The Labour Ministry said there had been 337 instances of industrial action so far in 2004, with more workers threatening to strike.

Economists have complained that unions are asking for too many concessions.

More, please

More than 7,000 Korean subway workers are reported to have walked out after demanding a pay increase of up to 10% even as their number of weekly working hours is set to decrease.

They also want the company to take on more employees to improve safety.

Commuters, however, were spared too many problems on the transport networks in Seoul, Inchon, Pusan and Taegu after non-union workers were drafted in.

The strike at the LG-Caltex refinery, meanwhile, began on Sunday after several rounds of wage talks collapsed.

The plant, a joint venture between South Korea's LG and Chevron Texaco, accounts for about 25% of South Korea's refining capacity and usually produces 650,000 barrels a day.