Warfare between factions in Zimbabwe's military came to at least a temporary halt today after six days of clashes, according to reports from the embattled southwestern part of the country.

Schools and stores reopened in Bulawayo, the country's second largest city and a bastion of support for Joshua Nkomo, leader of the minority party in the government coalition. Residents of Entumbane, the African township where the fiercest fighting occured, began to return to their homes, some reduced to rubble.

The area remained tense. Thousands who fled the fighting yesterday camped out in the streets of Bulawayo. Tonight, however, many fled again amid rumors that there would be renewed conflict.

Scores of heavily armed guerrillas loyal to Nkomo were still at large in the township and there were unconfirmed reports that they had been joined by reinforcements.

The death toll in Entumbane alone was reported to be about 100, although it is likely to be days before any accurate overall casualty figures are known. Scores of casualties have been reported from other sites.

The six days of fighting disintegrated three battalions of the country's new national Army and threw into question the ability of Prime Minister Robert Mugabe's government to unify the rival military factions, which are divided along tribal lines.

Mugabe has the backing of the dominant Shona tribe, while most of Nkomo's support comes from the southwestern area where the Ndebeles, who make up about 20 percent of the population, live.

The next few days will test whether Nkomo can still control his guerrillas who have refused to obey orders from their senior commanders to end the rebellion. Many of his troops are bitter because his party has been relegated to the role of a minor coalition partner since Mugabe's overwhelming victory in last year's independence elections.

Mugabe had to call into action a battalion of the white-led former Rhodesian Army, which his and Nkomo's guerrillas fought for seven years, to quell the fighting. In effect, the fighting gave the Rhodesian African Rifles, the mainly black forces of the former white government, a chance to even some scores.

That could lead to further difficulty in Mugabe's delicate efforts to integrate the more than 40,000 men under arms in the country but with divided loyalities. So far a dozen battalions of Mugabe's Zimbabwe African National Liberation Army and Nkomo's Zimbabwe People's Revolutionary Army have been nominally integrated into the new army. The Rhodesian African Rifles have not yet been brought into the process.

The African Rifles disarmed two of the affected battalions when it stopped the rebellion.

The third battalion and major remaining point of difficulty was at an army camp at Connemara, about halfway between Salisbury and Bulawayo, which was taken over by troops loyal to Nkomo earlier this week in a battle in which at least 36 soldiers were killed.

Responding to an ultimatum to surrender or be bombed by the white-officered air force and shelled by tanks, the rebel troops agreed to negotiations, which continued throughout the day.

Nkomo told a press conference in Bulawayo today that the troops in the two battalions around Bulawayo would be separated on the basis of their tribal loyalties to him and Mugabe and be put on opposite sides of the city about 40 miles apart. He also said the guerrillas in Entumbane would be separated. This could prove to be far more difficult because they have not been disarmed and there have been disturbances between the former guerrillas who live in the township while waiting to be integrated into the army.

Last November 58 persons were killed in and around Entumbane when the two factions clashed.

The death toll in this week's fighting is bound to be far higher. It also marks the first time that tribal divisions have flared into armed warfare among the troops being integrated into the new army under British supervision. a

There was no immediate confirmation from the government of Nkomo's statement about the separation of the factions but it is believed that he is coordinating closely with Mugabe, who also serves as defense minister.

The trouble began last Saturday with a beerhall brawl between Mugabe men in the national army and former guerrillas loyal to Nkomo who are at a rehabilitation center. From there it spread Sunday to soldiers from both sides within the army.

Nkomo's elements then advanced toward Bulawayo from both the north and the south where they are temporarily living in assembly camps awaiting integration into the army.

The African Rifles clashed with the forces advancing from the south in three Soviet-built personnel carriers and destroyed the vehicles. There have been no reports on casualties.

The Nkomo loyalists advancing from the north near Victoria Falls were in 11 personnel carriers and refused to obey orders of their overall commander, Lookout Masuku, to turn back. Just what has happened to them is unclear but they are believed to have dispersed into the bush.

The heaviest fighting occurred at Entumbane where the Rifles cordoned off the area and opened fire on the Nkomo loyalists' positions, according to reports reaching here.