June 21, 1986

It is 10 o'clock on a Saturday morning and the parade of the children is beginning at Houston Intercontinental Airport. Here comes 12-year-old Scott Craiger, skateboard hung rakishly over knapsack, on his regular filial pilgrimage from Wilmington, Del., where he lives with his mother, to spend the summer with his father in San Angelo, Tex. ''I've been flying alone since I was 5,'' he says with aplomb. Next comes tousle-haired Alvin Devore, 11, bound from Cleveland to visit his father in Irving, Tex. At airports all over the country young children, clutching favorite toys and dolls, are traveling alone in record numbers with the end of the school year, according to airline spokesmen. Continental Airlines, based in Houston, says the number of ''unaccompanied minors'' on its routes was up by nearly a third in the first two weeks of June over the same period last year. Other major airlines, while lacking detailed figures, all confirm the trend.

Several former officers of the Nicaraguan rebel forces assert that their top military leaders are siphoning off large amounts of money received from the United States, to enrich themselves at the expense of their troops. Furthermore, some of these former officers said, American officials have been warned about the abuses for years, ever since the Central Intelligence Agency began financing the rebels clandestinely in the early 1980's, but have continued to back the rebel leaders who are believed to be involved. A total of $27 million has been appropriated by Congress for nonmilitary aid in the current fiscal year, and a request by President Reagan for $100 million, including $70 million in military aid, depends on approval by the House next week. 'A High Life' Interviewed in the Miami area in the last few days, the former officers of the contras, as the rebel forces are called, said their assertions of corruption were based mostly on their experiences in the field. They described the use of phony receipts, black market currency deals, the substituting of inferior goods and other techniques.

The senior Soviet Air Force officer in the United States was ordered expelled from the country today after he was caught in what Federal agents described as an elaborate counter-espionage operation. The officer, Col. Vladimir N. Izmailov, 43 years old, was apprehended late Thursday night by several agents of the Federal Bureau of Investigation as he tried to dig up secret documents left as part of the months-long operation. The documents had been buried next to a telephone pole in rural Maryland, officials said. They said the colonel had been meeting for months with an American Air Force officer who was masquerading as a top-level traitor but actually worked secretly for the bureau.

Doctors today removed two small polyps from President Reagan's colon in a routine examination to see if cancer had reoccurred in his large intestine. Mr. Reagan's physician, Dr. T. Burton Smith, said in a brief statement afterward that the 75-year-old President was in ''good health.'' The statement did not say whether the growths removed today were benign or malignant. The President underwent major abdominal surgery for cancer of the colon nearly a year ago, on July 13. In January three polyps, or growths, about the same size as those found today were removed.

Overriding the opposition of the country's two nonwhite chambers of Parliament, South Africa's white leaders tonight forced into law two security measures that give the authorities sweeping powers to deal with unrest. The new measures enable the authorities to detain opponents for six months without trial and to declare ''unrest areas'' in which the police will have virtually unbridled freedom of action. Under existing law, the authorities had the right to detain people without trial for 14 days in nonemergency situations. Critics of the two laws approved by the white-dominated President's Council, the powers of which are superior to Parliament's, say the measures will enable President P. W. Botha to call off the nationwide state of emergency while retaining unfettered police control of black townships and squatter camps in which people will have few if any civil rights. Bitter Denunciation of Bills Human rights activists, many of whom are now in hiding or in detention under the state of emergency declared last week, denounced the legislation when it was before Parliament. They said the laws would give the authorities the same powers they now have under the emergency decree without a formal emergency declaration.