The occasional thump of a rubber-bullet gun punctuated the continued looting and burning today as South Africans began to assess the toll of the bloodiest day of race rioting the country has seen since the Soweto disturbances of 1976.

The official death toll for yesterday's rioting rose from 14 to 29 as police found more charred bodies in burned-out buildings and vehicles. The number of injured has been estimated at more than 300.

Police kept in the background today in Sharpeville, a black township 40 miles south of Johannesburg that yesterday was the center of the rioting, although looting and burning continued here and in two nearby townships, Sebokeng and Evaton, where a number of buildings blazed all day. No further deaths were reported.

It was unclear how many of yesterday's victims died as a result of police action and how many from mob violence, although it was evident both led to many deaths.

The intensity of the violence was underscored by the discovery of the bodies of four people who the police said had been strangled. Another who had been stabbed was found near the home of the township's deputy mayor, Sam Dlamini, who was hacked to death on his front doorstep yesterday.

The violence erupted after 10 days of mounting tension, during which police clashed repeatedly with groups of black nationalists and students campaigning for a boycott of Colored (people of mixed race) and Indian ethnic elections that were held under a new national constitution that took effect yesterday.

The black nationalists have opposed the new constitution as a sham reform of the country's segregationist system because it excludes the blacks, who make up 73 percent of the population.

Yesterday, residents in a number of townships south of Johannesburg organized a stay-home demonstration to protest increased house rents and electricity rates. The violence quickly spread to seven other townships.

At first police tried to quell the rioting with tear gas and rubber bullets. As it increased, they began using live ammunition.

Heavily armed police reinforcements were moved into the townships, and gunfire continued late into the night. A senior government official said today that some troops were called in to help guard buildings, but he said they were later withdrawn.

Members of black community councils, which administer the townships, appear to have been singled out for attack. At least three were killed and homes of several were burned. Others went into hiding.

Observers said this was because they were regarded as collaborators for holding positions in the segregationist administration, and because they were identified with unpopular measures such as rent increases.

The government has been giving power to black community councils in the townships in an attempt to distance itself from such issues.

A pall of smoke hung over the riot-torn townships today as fires continued to blaze in dozens of buildings.

The streets of Sharpeville were still blocked with charred remains of barricades that the rioters threw up. Stones, bricks and other missiles from the rioting littered the streets and pavements.

With a frenzied excitement, people clutching bulging plastic bags and crates of soft drinks spilled out of a squat brown building with a faded sign over the door that said "Solly's Studio and Cosmetic Center."

As they scurried by, a young man put down a heavy crate and held out a soft drink. "Have one, white man, they're going free," he called with a grin, then snatched up his crate again and ran down a side street.

Within 15 minutes Solly's Studio, a kind of corner grocery, was stripped of its stock. The barred front door, its locks broken, was left flapping on its hinges as the scores of looters disappeared.

The situation in Sebokeng and Evaton, about 10 miles away, was more tense. There were police roadblocks outside both townships and whites were warned not to enter.

"Don't go past that bridge," warned a plainclothes policeman on the road to Sebokeng. "They're busy burning cars over there."

An hour later, housing for black migrant workers just beyond the bridge was set on fire. A teachers' training college and a medical clinic in Evaton also were burned.

By late afternoon, residents said that every food store in the three townships had been destroyed or looted of its stock. Buses had stopped entering the townships, which have a combined population of about 1 million, and people had to walk miles to stores in white areas to buy supplies.

Aaron Sita was interviewed as he returned to Sharpeville carrying two large bags of groceries he had bought in the white town of Vereeniging, 10 miles away.

"I don't know how we are going to manage," he said. "It will be a long time before there is food here again."

Sita said he had seen two children killed by police gunfire outside his house during the rioting in Sharpeville yesterday.

"Some other children ran into my house to hide, but the police came in and found them and took them away," he said.

Majid Padat and his family spent today sitting in their automobile parked on the highway outside Evaton, watching their property burn less than 100 yards away.

The Padats are Indians who have lived in Evaton all their lives. In partnership with three other relatives, Majid Padat has two auto dealerships there.

Friday night, he said, pamphlets produced by an organization called "The Concerned Residents of Evaton" were slipped under their doors asking them to join the rental protest by keeping their businesses closed Monday.

"We did what they asked," said Padat. "We closed our businesses and went away for the weekend. Then friends phoned to tell us our property was being looted and burned -- our houses, offices, the lot. All I have left are the clothes I am wearing."

A total of 45 Indian businesses in Evaton were destroyed. As Padat talked, other Indians told similar tales in bewildered tones.

They were asked if they thought the blacks had singled them out for attack because the Indian community has been given a role in the new constitution while blacks have not.

One man who would not give his name answered angrily, "Absolutely not. You whites should spend one or two days among the blacks here and learn how they feel about you. People can take so much oppression and frustration and then they explode."

In none of the townships did the violence spill beyond the borders of the segregated black area.