Murder has passed accidents and any single disease as the leading cause of death among young nonwhite men in the nation's metropolitan areas, according to a report published yesterday in the New England Journal of Medicine.

"The national increase [Between 1960-1970] in homicide mortality in this population group was 80 per cent," said the report.

It added: "Nationally . . . [homicide] rates have increased dramatically for both sexes and among whites and non-whites, with the greatest absolute increase occurring in nonwhite men . . ."

The report was based on a study of homicide in Cleveland and 56 of its suburban commmunities from 1958 to 1974. But the researchers - most of them doctors at Case Western Reserve University - said the Cleveland figures reflect national trends.

The homicide trends reported this study shock us," the researchers said. "What has happened in Cleveland reflects, in a magnified way, national trends during the same period."

In Cleveland about 98 per cent of "nonwhites" are black.

Between 1958 and 1962, 82 of every 10,000 black Cleveland men between the ages of 25 and 34 died as the result of "international violence," the report said That figure rose to 344 of every 10,000 betwen 1969 and 1974, according to the report.

An estimated 13 per cent of all homicides in Cleveland between 1958 and 1974 could be called legally justified, according to the report. Most of the justifiable homicides were by police, and most of the persons killed in those incidents were blacks, the report said.

However, the report noted that white Cleveland men have also begun to get killed with increased regularity. 'The greatest relative increase [in Cleveland homicides during the complete study period] occured in white city men - 445 per cent. Their rate now surpasses that of nonwhite women, altering the traditional ranking of race-sex homicide mortality found in Cleveland and other urban communities," the report said.

The report attributed the upsurge in homicides - which it said has abated somewhat in recent years - to the ready availabilty of handguns.

"Guns are so numerous in the United States that at least half of all American homes harbor at least one firearm," the report said. "A handgun in the home is more likely to be used in a domestic homicide or to cause serious injury, intentional or accidental, than to deter a robber or burglar," it said.

The report offered no sociological explanation for the preponderance of nonwhite homicides in Cleveland and elsewhere. However, such an explanation was forthcoming from Dr. Alvin Poussaint, a nationally known psychiatrist at the Harvard Medical School, who has specialized in studying mental problems in the black community.

"A lot of it," said Poissaint, "stems from the historical problems that have effected blacks - racism, joblessness . . . People living in frustration tend to turn on one another.

"A lot of it has to do with manhood struggles - the 'Who's going to save face kind of a thing.' Sometimes, it [a murder] can happen over an argument over the quarter."