Five persons were killed and more than 60 injured in a black South African settlement today as a resurgence of racial unrest shook many parts of the country.

The worst clashes were in Crossroads, outside Cape Town, where residents reacted violently to a government statement that sparked fears that they were about to be removed from their homes.

Today's violence, part of a flare-up of disturbances over a widening front during the past few days, contributed to a growing sense that South Africa may be in danger of sliding into a state of chronic racial unrest.

Four months of major unrest, which subsided briefly through January, followed the introduction of a controversial new constitution last August. Now some senior security officials are saying privately that unrest must now be considered "endemic" in some black areas, particularly ghetto townships to the south and east of Johannesburg.

In Crossroads today, riot police opened fire with rubber bullets and birdshot. Tear-gas launchers and helicopters hovered as angry crowds gathered in the streets, with men refusing to go to work because they said they feared that their families would be uprooted while they were away.

This followed a day of trouble in Katlehong township, east of Johannesburg, yesterday, when police opened fire on a crowd of 2,000 black residents demonstrating against the banning of a meeting to protest a rent increase. Two of the demonstrators were killed and one was wounded.

In a separate incident yesterday, rampaging students set fire to their school in a black township outside the town of Kroonstad, in Orange Free State.

On Saturday, riot police opened fire with shotguns on a crowd of striking black workers at a gold mine west of Johannesburg, wounding 100.

An undisclosed number of striking miners were injured when police opened fire on them with rubber bullets at a mine near Witbank in eastern Transvaal Province on Saturday.

What worries security officials even more than the violence in the ghetto townships is that the trouble is spreading into the smaller towns of South Africa's central farming areas -- this country's equivalent of the American Midwest -- where for generations the black communities have been isolated from the political consciousness of the cities.

Now, a number of these communities are also staging angry demonstrations and clashing with police.

Authorities fear that if this kind of trouble continues to spread over a country three times the size of California, the security resources of the ruling white minority could start to become thinly stretched.

There appears to be no single issue behind the latest surge of unrest, except for a seemingly pervasive mood of black anger.

One recurring theme in many of the trouble spots is the system of segregated education, which the white government insists on maintaining and which young blacks believe means inferior schooling for them despite efforts by the administration to upgrade standards.

Another factor, observers believe, is South Africa's deepening economic recession.

A sharp decline in the value of the local currency, the rand, against the dollar resulted last month in a 40 percent increase in the price of imported gasoline. The ripple effect is causing inflation to soar toward 20 percent, while the estimated black unemployment rate is well over 30 percent.

Hard-pressed black workers resent having to pay more in bus fares to get to work from the distant black townships, where they are required to live under the segregationist system known as apartheid.

This, plus rent increases for the state-owned houses most of them occupy in the separate townships, have been behind a number of the demonstrations that riot police have quelled with rubber bullets, tear gas and sometimes shotguns.

There has been sporadic trouble in Crossroads since a shortage of government housing for blacks drove thousands of homeless people to build a township of rudimentary shelters outside Cape Town in 1975.

Officials of the white administration have threatened to remove what they regard as an illegal "squatter camp" but the community, which has grown to approximately 50,000, has put up a spirited resistance.

Three weeks ago a new minister in charge of black affairs, Gerrit N. Viljoen, announced that the government was suspending the forced removal of a number of black communities pending a review of its population resettlement program, but he said "squatter" communities such as Crossroads would still have to go.

The people of Crossroads are scheduled to be moved to a new township called Khayelitsha, about eight miles farther from Cape Town, but they seem determined to resist.

On Friday, Viljoen said additional staff and transportation were being provided to speed up preparations for the removal of Crossroads residents to Khayelitsha.

This seems to have sparked fears among the residents that their removal was imminent. Thousands began demonstrating in the streets today, stoning buses and setting up barricades of burning tires.

In an attempt to calm the situation, Viljoen issued a statement today denying that the people were to be removed "immediately." He made clear that the government still intended to move them, but said it would provide timely notice.