South Koreas's military leaders announced the arrest of 17 more prominent politicians and the dismissal of 431 bankers, brokers and insurance officials from their jobs today in the latest phase of a widening national purge.

The announcement from the martial law command accused the political leaders, including three former Cabinet ministers and senior legislative leaders of both major political parties, of "polluting the political atmosphere through various irrational and corrupt acts" and amassing private fortunes from public service.

The business officials, reportedly including four bank presidents, were dismissed in a government-directed drive instigated and masterminded by the military-dominated Special Committee for National Security Measures. The special committee, established May 31, is a shadow government whose standing committee chairman, Lt. Gen. Chon Doo Hwan, is believed generally to be the most powerful figure in the country.

Chon and his fellow generals have ousted more than 300 South Korean Central Intelligence Agency officials, including 33 of 40 overseas station chiefs; 232 high-ranking civil officials, including the minister of commerce and industry; and 4,760 lower ranking officials such as tax collectors and customs agents.

The most spectacular dismissal, announced one month ago today, was the purge of nine top officials of the government of assassinated president Park Chung Hee and confiscation of their fortunes. Former prime minister Kim Jong Pil, one of Park's closest associates, was forced to give up $36 million in cash and property, including 34 secret bank accounts, ownership of a Seoul daily newspaper, an orange grove and a livestock farm. Former KCIA chief Lee Hu Rak, who once explained that "when you bake a cake, some flour sticks to your fingers," had to give up $32 million in illegal gains. Park's longtime bodyguard, Park Jong Kyu, gave up a $12 million fortune.

The military-directed plunge into the waters of "national purification" is expected to continue in coming weeks with a purge of state-run corporations and unofficially reported planned purges of educational institutions and 150 to 160 members of the press.

While the executive branch of government might not have legal authority to sweep out the legislature and private institutions in a Western political system, nobody has quibbled with the power of the South Korean military to order or direct such measures under the prevailing martial law.

The public, in fact, has generally cheered the cleanup, particularly the ouster and humiliation of high officials who had been untouchable under the Park government. The actions against less well known figures were less enthusiastically applauded, but they are still broadly popular by all indications.

It is evident to observers here that the continuing purges serve several purposes for the military leadership.

First, they are a means of winning popularity and legitimacy in the eyes of a populace that did not generally welcome renewed military domination after 18 years of the strict Park administration.

Second, the current drive and threat of more to come are a means of establishing positive loyalty in a public and private bureaucracy that grew up under the previous leadership.

Some of those purged, both in political ranks and the bureaucracy, had been considered obstacles to full control by the new leadership. The obvious lesson is that anyone showing signs of disloyalty can expect to be severely penalized.

Third, the "purification" efforts respond to the ideas and instincts of a new military leadership that is considered to be genuinely puritanical, in keeping with their relatively spartan former life as field commanders. They are believed to be contemptuous of the perceived easy life of the purged.

According to government insiders and other observers, only a small proportion of those purged are believed to have been actually corrupt beyond the accepted standard of the day. Some evidently were dismissed for disloyalty, others for incompetence or simple unpopularity among colleagues in their agencies.

Officials profess not to know exactly who decides on those to be eliminated from public life, except to say that the final orders come from the military-dominated special committee. However, several bureaucrats said that some of those eliminated appear to have been chosen by superiors in their own agencies.

The current drive is remarkably similar to one of the techniques used by the later president Park to cement his initial support after taking power in 1961. In the early days of his leadership, Park's Supreme Council for National Reconstruction arrested 2,000 politicians, 17,000 civil servants and 2,000 military officers. About 41,000 officials eventually were fired.

This time the Army has been immune, except for several dozen top-ranking generals who were summarily retired in December after they were overwhelmed by younger generals, the current leaders.

The allegations of corruption and enrichment have not touched the late president, who was sponsor and a father figure to some of the most important of the new leaders. Park's son-in-law, former ambassador to Canada Han Byung Ki, was reported to have been arrested for interrogation in May but later released, and some figures close to Park's daughter Kunyoung are reported to have been called in for questioning. But no word of this has appeared in the censored press.

According to South Koreans familiar with the family, there is no sign that Park left riches in this country. His daughters are said to be living in a Seoul house that was his private residence prior to the 1961 coup. Reportedly, he did not leave either a military or a civil pension due to technicalities of Korean law. There are indications that the government will pass special legislation to aid his family.

Nobody is certain if the Ultimate effect of the current purification drive on the South Korean public and private bureaucracy will be greater responsiveness to the leadership and public, or simply greater sluggishness and caution. Bureaucrats seem to have accepted the purges as a fact of life, with no outward signs of resentment, but it is hard to know what they are thinking.

Those who have escaped the axe are clearly relieved.Among bureaucrats in Seoul, a common greeting, only half in jest, is, "How nice it is to see you again this morning" -- as if routine meeting these days are in doubt.