When Rhodesia finally gained its independence as the black-ruled nation of Zimbabwe in April after a bloody guerrilla war, the country's new prime minister, Robert Mugabe, pronounced a policy of reconciliation.

"The wrongs of the past must now stand forgiven and forgotten," he said in a moving address.

Seven months after independence, reconciliation seems to be working fine for the whites who fought Mugabe for years.

Ironically, it is not working very well at all for one segment of blacks, Joshua Nkomo's Patriotic Front party, which joined forces with Mugabe's party in a tenuous alliance to overthrow white-minority rule.

Nine senior members of Nkomo's party were arrested Friday, thus becoming the first political detainees under the black government. The experience should be familiar, as they were also held by former prime minister Ian Smith's white government.

Although the government refused to comment on the arrests, Mugabe supporters said the move was in retaliation for recent clashes between former guerrillas loyal to Mugabe and Nkomo in Bulawayo, the country's second-largest city. Mugabe supporters have blamed the violence, which killed 58 persons, mainly civilians, on Nkomo loyalists.

More arrests are expected and some sources in Mugabe's ruling Zimbabwe African National Union (ZANU) think that even Nkomo, the father of Zimbabwean nationalism, eventually will be detained.

"Some foreigners will protest but they'll soon forget," one party member said.

Most informed members of Mugabe's party, however, believe that jailing Nkomo would be too drastic for Mugabe since both of them spent more than a decade locked up under Smith.

Meanwhile, Smith and other white former officials of the Rhodesian Front party are unscathed despite frequent pronouncements by Mugabe during the seven-year war that they would be tried for suppression of blacks. The reason for the difference in treatment is simple. Smith's party no longer represents a threat; Nkomo's party does.

One of the major, permanent changes during the first seven months of black rule is that the whites, the center of attention in this country for decades, have become irrelevant politically. They still wield considerable economic power, but their 20-seat parliamentary representation, long a key issue barring a settlement in Zimbabwe, has become meaningless.

"There is no chance for them to rule," a Mugabe supporter said.

Not so for Nkomo's Patriotic Front, which Mugabe supporters believe has not accepted the results of Mugabe's landside election victory in February, giving him 57 seats to 20 for Nkomo.

The Patriotic Front "will be crushed within the next few months," one party source said. Another, more realistically, said the party will probably be allowed to limp along until Nkomo, 61, retires or dies.

Radical ministers in Mugabe's government have campaigned openly for the Patriotic Front to be eliminated.

Recently, controversial Manpower Minister Edgar Tekere, on trial for the murder of a white farmer, said Nkomo was in the government simply as a matter of "charity." Finance Minister Enos Nkala, speaking in Nkomo's Bulawayo heartland, called for the formation of a one-party state.

It is unclear whether Tekere and Nkala are point men for Mugabe or out on their own, since Mugabe's method of leadership is similar to that of a committee chairman -- allowing all voices in the party to be heard and then taking action, often behind the scenes.

Mugabe, however, seemed to reach a turning point earlier this month after the clashes in Bulawayo, the worst violence since independece.

In an angry, one-sided speech to the nation, he blamed the Patriotic Front for the troubles and made no reference to inflammatory speeches by Nkala, who called for a virtual state of war against Nkomo's party.

That has been followed by the arrests of the Patriotic Front officials and a reported decision to disarm the former guerrillas loyal to both parties who are awaiting integration into the new national Army.

The move is bound to be difficult since the troops have a vast array of weapons, but the political effect of disarming both sides will mean that Nkomo has lost another base of strength.

Nkomo's problem is that his party has become identified with the minority Ndebele tribe located in the southwestern part of the country while Mugabe represents the Shonas, who made up almost 80 percent of the population.

With tribalism such a strong factor in African politics, the Patriotic Front has no realistic possibility of gaining elected power.

"Ndebeles will have to join ZANU or get out of politics," a Mugabe supporter said.

The Patriotic Front is showing acute signs of atrophy.

During the campaign for the February elections, the party headquarters was a beehive of activity.But despite this weekend's provincial elections in much of the country, which will give blacks control of local government for the first time, the party's Salisbury office was like a morgue all week.

The party has not been able to pay its staff for four months and has had to close down its weekly newspaper.

Key Nkomo aide Willie Musarurwa, who has been keenly interested in Zimbabwean politics for more than two decades, said: "I'm not interested in the elections. People are reading too much significance into them."

Musarurwa indicated that he would be willing to abandon Patriotic Front politics if he received a government job.

In contrast, Magabe's party is making an all-out effort to use the provincial elections to bolster its support.

The elections are being carried out under the supervision of Eddison Zvogbo, the minister of local government and housing, who organized the February campaign that swept Mugabe to power. The Patriotic Front has complained that using an official in this job gives Mugabe's party an advantage.

In a recent interview Zvogbo had little difficulty in combining his government and party roles. His office was be-decked with skirts and dresses bearing the party emblem to be worn by supporters during the campaign.

Zvogbo said the party is seeking "to extend our political control" and added that "if Nkomo cannot win in Bulawayo, he and his party are doomed because they can't win any other city."

That verdict will have to wait since black elections in Salisbury and Bulawayo have been postponed because of the recent violence.

A lower-level Patriotic Front member summed up the elections and, more importantly, why the Patriotic Front and its armed supporters are still regarded as a threat by Mugabe's party.

"No government in Africa has ever been removed by elections," she noted, clearly implying that a coup was the party's only route to power.