Armed Indian vigilantes clashed repeatedly with black rioters here again today, as at least 30 more people died in what has now become the worst round of violence to hit this country since political unrest erupted 11 months ago.

Some of the heaviest fighting occurred in the Phoenix township northwest of this port city where mobs from the two factions fought a pitched battle with guns, rocks, clubs and machetes on a hill overlooking the township and at the historic Gandhi settlement nearby. The site, founded by Indian independence leader Mohandas K. Gandhi, was later looted and burned.

The death toll during four days of intensifying interracial violence now is at least 54, according to tallies from area hospitals, with as many as a thousand injured. Other corpses may lie amid the charred ruins of houses and shops in townships that have become off-limits even to the police and Army.

The security forces have appeared outnumbered and at times confused, and those in evidence today often seemed more intent on containing the unrest within township borders than confronting the rioters.

Billows of smoke from burning buildings dotted the rolling hillsides this afternoon and as darkness fell, Indians armed with pistols and rifles stood watch on the ridges separating their besieged community of Phoenix from the slums of the black townships of Kwamashu and Inanda.

Earlier in the day, the Indians had sealed off access to the area by firing on blacks with shotguns and pistols, according to witnesses, while armed vigilante squads in cars drove into crowds of looters at nearby shops and opened fire. Some blacks were wounded, but there were no reliable reports of casualties.

The conflict presents South Africa's white-ruled government with a new crisis only two days after police spokesmen were claiming that violence in the country had eased since a state of emergency was declared July 21 in 36 cities and towns. The government now faces the prospect of either broadening its emergency decree to new areas or finding another strategy to cope with the escalating unrest, in the view of analysts here.

The violence also casts doubt over President Pieter W. Botha's reported plans to announce a package of new political reforms at his ruling party's provincial congress here next week. Analysts say Botha had hoped a return to relative peace would allow him to go ahead with the proposals without appearing to have bowed to pressure.

The political dimensions of the crisis were underlined tonight in a tough new statement by one of the area's principal leaders, Chief Gatsha Buthelezi, whose Zulu followers roamed the streets of several townships today battering opponents with spears and clubs, according to witnesses, and seeking to enforce an uneasy peace.

A political moderate caught between the rightist white government and its militant opponents, Buthelezi condemned the unrest and the radical black factions he claimed were behind it. But he emphasized his view that the chief culprit was the government because of its refusal to negotiate genuine reform of its apartheid system of racial segregation with black leaders like himself.

"We are as much reaping the whirlwind sown by white political ineptitude as that sown by those committed to violence for political purposes," the statement said.

"Just as it was wrong for blacks to turn anger into murder and destruction it was wrong for whites to maintain a political system in which rising black anger was an inevitable consequence of the whites' refusal to share power," it added.

The clashes today in Phoenix and at the Gandhi settlement -- founded by the advocate of nonviolence during his years as a lawyer in this country at the turn of the century and including a health clinic, school and farm -- reflected both the rage and the political complexities of this new round of unrest. It has pitted Indians against blacks, and Buthelezi's followers against supporters of the multiracial United Democratic Front, whose activist antigovernment ideology clashes with that of the chief's Zulu-dominated Inkatha movement.

Accounts differed on how the battle began. Mewar Ramgoban, the settlement's director and national treasurer of the front, said dozens of Indians seeking revenge for the burning of their homes and shops earlier in the week had invaded the property to attack the homes of blacks who live there. He blamed the ensuing battle on "agents of the system," meaning the government.

But some residents said a mob of black rioters first stormed the center, setting off retaliation by the Indians.

By 10 a.m. the two sides were battling amid the settlement's historic buildings. Rocks rained on the roofs and ground with the frequency of automatic rifle fire and Ramgoban was slightly injured by one when he made a futile effort to stop the clash.

He fled to a nearby shopping center where he pleaded with police to go to the scene. Fatima Meer, an Indian sociologist and political activist who was trapped at the settlement for several hours, said she called the local fire brigade for help but was told the firefighters had strict orders not to enter the area.

Ramgoban, a defendant in the recently adjourned treason trial of 16 United Democratic Front leaders, also came under vehement attack from fellow Indians at the shopping area, who complained that the front had offered them no protection from blacks. "Where were you when our houses were burning?" shouted Krishna Govinder. "You're the people who caused this for us."

More than 500 Indian families have been forced to flee their homes in Inanda over the past three days to escape black rioters, in a scene reminiscent of riots in 1949 when nearly 140 blacks and Indians died. Front officials have called for a restoration of peace in the area but have been unable to control the largely leaderless mobs of looters

Front leaders argue that the rioters, who come from the city's poorest areas, are looting indiscriminately and targeting Indians because of their relatively greater wealth, not because of racial animosity. But many Indians do not agree.

"I've lost everything," said David Maharaj, whose family was ferried from Inanda by rescue workers in an armored vehicle Wednesday night. "There was so much looting you just had to run.

"The blacks have no excuse. I know they have something against the system, but against us they have no excuse at all."

By this afternoon, at least 10 structures were ablaze at the Gandhi settlement and blacks could be seen carrying off furniture, office equipment and tin roofing. The bungalow where Gandhi once lived was completely empty, its windows shattered. Photos of him were strewn on the grass outside.

The violence started earlier this week and intensified on Wednesday after a large squad of Inkatha followers attacked a United Democratic Front memorial service for a black civil rights lawyer who was slain last week by unknown assailants. Many front members blame Inkatha for fanning the violence, just as Buthelezi blames the front.

The Zulu chief, recently returned from a trip to London and Washington, called on all sides to eschew violence "before it is too late," but warned that his supporters were prepared for further fighting. "We reserve the right to defend our persons and property against the onslaught now being mounted against us," he said.

Other incidents were reported outside the cities of Port Elizabeth and Middleburg and in Soweto, the country's largest black urban center. In Cape Town, university students marched for the second straight day to protest the government's state of emergency. Police used tear gas to disperse the marchers.

Meanwhile, pamphlets began appearing in Johannesburg and Pretoria calling for consumer boycotts of white businesses beginning Monday in an attempt to use black buying power to pressure the government to suspend the emergency decree. The pamphlets in Pretoria also called for a general strike beginning Saturday and continuing through Monday.