An independent labor organization trying to raise wages of South Koreas low-paid factory workers is encountering arrests, sporadic violence and heavy government pressure.

Its leaders accuse the government and factory management of attempting to suppress their church-sponsored movement as part of a campaign to keep wages low and assure the continued competitiveness of South Korean exports.

In the past few weeks, prosecutors seized books and records of the Urban Industrial Mission and arrested one of its ministers for delivering a sermon deemed critical of the government.

Books widely circulated with government permission accuse the mission of being tainted with communism, the most serious charge that can be made in this country which shares an armed border with North Korea.

Young women demanding the right to strike were arrested at an Easter worship service. Other were showered with human excrement thrown at them during a plant-organizing election.

An American minister from Japan was detained for six hours and his papers were confiscated after he visited a mission seminar here.

The mission is an international church-sponsored organization that assists low-paid workers in urban areas of Japan. South Korea, Hong Kong the Philippines, Indonesia, Malaysia and Thailand. It is financed by local churches, the World Council of Churches and denominations in Australia, the United States and Europe.

In South Korea, its targets are the textile factories, which in the 1960 launched this country's formidable cconomic boom and which still account for a large share of the profits in the export trade.

Much of those plant's competitive success is due to the low wages paid to young women workers who tend the machines. One recent survey found the woman textile worker earns an average of $73 per month. Many work eight-hour shifts seven days a week with only an occasional offical holiday for rest.

Strikes are forbidden by national law and the government has a hand in setting wage levels. In an interview, an offical acknowledged that it is government policy to increase wages slowly so as not to upset the favorable competitive position of South Korean products. At this stage of development, be contended, wages must be kept low to retain makets eagerly sought by other Asian countries. He said strikes cannot yet be permitted but he denied the government is bent on suppressing. The Urban Industrial Mission.

Government pressure and the docile behavior of officially sanctioned trade unions prevented any significant labor agitation until the early 1970s, when the young women workers, aided by the mission, began demanding union elections and collective bargaining rights. Their leaders are under surveillance by the Korean Central Intelligence Agency and local police and the pressures have increased in recent weeks.

On May 1. police from the public prosecutor's office entered the mission office and seized lists of members enrolled in its credit union, the major record of persons having connections with the organization. They also took large number of other documents and pictures from the walls.

A government spokesman said he could not supply an explanation of that incident.

Mission leaders, who asked not to be identified, said their organization had recently refused to submit to an audit of its credit union of grounds the lists of members would be turned over to the KCIA.

The same day, a mission minister, the Rev. In Myung Jin, was arrested for a sermon given two weeks earlier and was charged with violating Emergency Proclamation Number 9, which prohibits any crisicism of the government or the constitution.

The sermon had questioned administration of justice and had criticized in particular on prosecutor, now deceased for harsh treatment of political dissidents.

In a tape recording left with friends before he was being singled out for his activities with the mission. It was he who had initially refused to have the organization's credit union audited.

The mission had also come under strong attack in a recently published book widely circulated among workers in textile mills and other plants where mission supporters have been agitating.

The book charges that the mission is part of a communist plot and that its theology is not based on Christianity but on the communist-red ideology." It also charges that the World Council of Churches is dominated by persons having allegiance to communism.

Mission say the book is a government dervice to discredit their orgainzation in this staunchly anti-communist country. No book can be published and distributed legally without government approval.

Six women from several plants were arrested March 26 at an Easter religious service where they suddenly seized microphones and demanded the right to strike and bargain collectively. They were charged with interfering with a religious meeting.

On Feb. 21, during union elections at the Dong-II plant, a group of men burst into a textile workers' office, destroyed machinery and threw human excrement on many of the women. The women said their assailants had been hired by the officially sanctioned textile union in its effort to retain control of the plant.

In the most recent incident, the Rev. John Walker, and American missionary from Kobe, Japan, said he was detained for six hours by questioning at Seouls airport as he was leaving after attending a mission seminar late in May.

He said government agents confiscated mission documents and his personal notes on meetings he had attended and threatended to charge him with violating a proclamation that prohibits criticism of the government.

A government spokesman, asked to esplain the incident, siad Walker's papers had been uncovered during a routine search by police and customs agents and were found to include 244 copies of 63 documents. The papers "slander or oppose the constitution and criticize government activites," the spokesman said, during that it is illegal to carry such material in or out of the country. The U.S. Emabassy has asked for an explanation of Walker's detention.