SEOUL Labor unrest spread in South Korea on Tuesday as workers in the auto and other industries joined a strike against the privatization of state firms.

Ignoring government warnings, workers at south Korea's biggest car firm, Hyundai Motor Co. and its sister firm Kia Motors Corp., walked out Tuesday in support of state workers protesting against a government privatization plan.

Hyundai said 22,000 unionists in the southeastern port of Ulsan downed tools from 1:00pm (0400 GMT) for a four-hour stoppage.

The Hyundai and Kia unions are affiliated with the Korean Confederation of Trade Unions (KCTU), South Korea's second largest labor group, which has called a strike by 100,000 members.

YTN television news said 50,000 workers across the country were on strike. The Korean Confederation of Trade Unions (KCTU) said 130,000 members would walk out for protest rallies in 22 cities.

The South Korean government has said the two day old strike is illegal and ordered the arrest of 36 union leaders. Dozens of union activists have taken refuge at Myongdong Cathedral in Seoul or gone into hiding.

Some 8,000 state workers are blockaded by riot police in two university campuses in Seoul.

While the Federation of Korean Trade Unions (FKTU) held talks with the government the rival KCTU warned it would call out more workers if the government rejected demands to stop privatization, cut working hours and increase pay.

The strike has forced the cancellation of an estimated 60 percent of rail services but the government has mobilized non-union workers to keep power stations open.

Extra buses and planes have been brought into service. But commuters have jostled to get a space on rare trains heading into Seoul and roads into the capital and other major cities have been choked with cars.

As public anger grows, newspapers on Tuesday urged the government to take action, but President Kim Dae-jung called for patience in handling the unrest.

"We need utmost patience in dialogue with unions, although illegal and violent acts must be sternly dealt with," Kim told a cabinet meeting.

The government said only 29 percent of 30,000 unionists at railway and power services had joined the strike. Unions said 16,000 workers, including 5,400 at power firms, had walked out.

Union leaders, predicting massive layoffs, have demanded privatization be put off. Some 140,000 state workers, including 7,300 rail staff, have already lost their jobs in the past five years.

But the government has insisted the private capital is the only answer for most of the debt-ridden state firms due to be sold.