South Korean President Park Chung Hee was shot to death by a government official last night, and the country was placed under martial law early this morning, according to authorities here.

The Korean strongman, who had ruled for 18 years, was shot by the chief of the Korean Central Intelligence Agency Kim Jae Kyu during an argument at a dinner party, according to the report.

Government troops this morning occupied all important buildings; universities were closed, and all unauthorized meetings were banned.

The prime minister, Choi Kyu Huh, was named acting president after a Cabinet meeting early this morning. The streets of the city were calm.

The minister of culture and information, Kim Seong Jin, gave this version of the slaying:

Park was dining in a KCIA headquarters restaurant with the agency's chief. The KCIA director became involved in an argument with the president's cheif bodyguard, Cha Ji Chul. Kim began shooting and Park was wounded. He died on the way to an Army hospital at 7:50 p.m. [6:50 a.m. Edt.]

The presidental bodyguard and four other men were also slain, the Information Ministry statement said.

Kim, the KCIA director, was arrested by martial law authorities.

The South Korean Cabinet was called into an emergency session at about 11 p.m. and made its first announcement more than five hours later.

The disclosure that Park was dead did not come for several more hours, or about 12 hours after the shooting reportedly occurred. There was no explanation for the delay. The government's first announcements this morning said only that Park had been "incapacitated."

The Cabinet announced that Prime Minister Choi had been designated acting president in accordance with the constitution.

A division of American troops stationed in South Korea was placed on alert. Seoul is approximately 30 miles from the Demilitarized Zone that separates South Korea from communist North Korea which has troops on the border.

The Carter administration issued a statement obviously directed at North Korea, warning that the United States "will react strongly in accordance with its treaty obligations to the Repbulic of (South) Korea to any external attempt to exploit the situation in the Republic of (South) Korea."

Senior Defense officials said that the South Korean Army appeared to hold power following Park's death.

U.S. officials said that South Korean Chief of Staff, Gen. Chung Sung Wha, had emerged as the key figure in Seoul following Park's death. Government officials in Seoul said that Gen. Chung had been named martial law administrator for whole country.

U.S. Defense Department officials said that Prime Minister Choi, whose position under Park was largely nominal, does not appear to have emerged with any increased power.

[The State Department issued a statement that said, "The United States regards the matter as an internal one for the Republic of Korea and urges restraint on the part of all."]

The announcement of Park's death stunned the capital, but there was no sign of any antigovernment activity on the streets.

The country had been racked by violent student riots at the southern cities of Pusan and Masan, but both cities were calm after Park had imposed martial law and ordered a roundup of those responsible.

The KCIA has long been a powerful force in South Korean domestic politics and had been considered loyal to President Park, who used the agency repeatedly to round up political disenters and to root out alleged subversives. r

The martial law proclamation promptly banned all unauthorized public gatherings, extended the nightly curfews from four to six hours, imposed nationwide censorship and ordered all ports of entry to be closely checked.

The streets of Seoul were busy with shoppers this afternoon and there were few signs visible that anything unusual had happened.Most citizens heard of the slaying only when they arose this morning and turned on radios.

The many small business shops in downtown Seoul were displaying small Korean national flags at half-mast and some of them were draped by black pieces of cloth signifying mourning.

A government spokesman said this afternoon that the cabinet had been called into another special meeting to plan a state funeral for Park.

Park's increasing authoritarianism has created strains between Seoul and the Carter administration, which has urged a relaxation of his rule.

Early this summer President Carter visited South Korea and is known to have urged Park to liberalize his government. Carter also met with 12 South Korean religious leaders, several of whom were known to have been opposed to Park's policies.

After Carter left, however, there was a new crackdown. The U.S. administration was particularly disturbed about a bloody police raid on opposition party headquarters Aug. 10.

At the start of his administration in 1977, Carter had ordered a gradual reduction of the U.S. ground troops in South Korea. That proposal was shelved this year following intelligence reports of a substantial buildup in North Korean military power.

Park, who was 62, had been the target of several assassination attempts. In January 1968, a commando group from North Korea snaked into Seoul and made an unsuccessful attempt to storm the Blue House, The South Korean presidential residence. Two days after that North Korean gunboats captured the U.S. spy ship Pueblo.

On Aug. 15, 1974, Park and his wife were attending a ceremony in the National Theater in Seoul, when a gunman tried to assassinate him. Park ducked under cover but his wife was killed.

The Korean peninsula, situated between China and Japan, has figured prominently in strategic planning for Asia. Since 1945 it has been divided at the 38th Parallel between the Communist North and the pro-Western government in the South.

World War II brought an end to the Japanese occupation of Korea but created the divided country that exists to this day. Soviet forces installed a communist government north of the 38th Parallel while the government in the South was headed by Syngman Rhee, who had long struggled to gain his country's independence from the Japanese.

Rhee aligned South Korea with the United States and was president at the time of the invasion by North Korean troops in June 1950.

Rhee's authoritarian rule created general unrest throughout the country. In 1960, student-led demonstrations sparked a popular upheaval throughout the country, which resulted in Rhee's resignation.

The government that succeeded him was led by Yun Po Sun as president and Chang Myon (John M. Chang) as prime minister. The new administration was plagued, however, by administrative chaos and in May 1961, although barely a year in office, was ousted in a bloodless coup led by then Maj. Gen. Park Chung Hee.

The country was governed for two years by a military junta led by Park. In an attempt to restore at least the facade of civilian rule, Park and other leading officers resigned from the Army and under the aegis of their newly organized Democratic Republican Party won the presidential and parliamentary elections of 1963.

A watershed in Park's rule was reached in 1971. After forcing through a constitutional change that enabled him to run for a third term, Park barely eked out a victory over one of his leading civilian critics, Kim Dae Jung.

In October 1972, Park declared a national emergency, proclaimed martial law and dissolved the National Assembly. He promulgated a new constitution that greatly increased the powers of the presidency. In next presidential election, in 1972, only a special group of public figures handpicked by Park was allowed to vote.

In the face of spreading unrest, Park issued a series of decrees that further restricted civil rights.One of the most sweeping was the decree of April 1974 that prohibited any criticism of the government or its policies. o

During Park's rule there was little if any relaxation in the tension between the two Koreas. The Demilitarized Zone between them is watched over by two massively equipped armies on continual alert. Over the years there have been frequent incidents as patrols from the two sides encountered each other.

North Korea has tried to infiltrate armed units in South Korea, some of them with the mission of creating an armed revolt in the countryside. They have met with no success, as much because of the conservative nature of the rural South Koreans than the vigilance of the country's military.

Radio Pyongyang, the official station of North Korea, led its Saturday morning news broadcast with a report of Park's death without comment, according to NHK, the Japanese broadcasting company.

[According to White House officials, President Carter received word of development in Seoul at 2 p.m. EDT]. National security adviser Zbigniew Brzezinski convened a meeting of the Special Coordinating Committee, the ad hoc crisis management group of the National Security Council. In addition to Brzezinski, the meeting was attended by Secretary of Defense Harold Brown, Deputy Secretary of State Warren Christopher, who sat in for Secretary of State Cyrus Vance, who was out of town; the Joint Chiefs of Staff, and Frank Carlucci, deputy director of the Central Intelligence Agency.

President Carter left for a weekend at Camp David before the meeting.

[The announcements warning North Korea and stating that the United States considered the matter an internal one for South Korea followed the Coordinating Group meeting.]

The last decade or so of Park's rule was marked by one of the highest economic growth rates in the world. A particular feature of South Korea's development has been the degree to which the increasing prosperity was shared by all social classes and geographical areas.

South Korea countered the soaring price of oil, of which it has none of its own, by an aggressive campaign of selling goods and services to the oil-exporting countries of the Middle East.