All former guerillas in assembly points in Zimbabwe have been disarmed, the head of the country's joint military command said today.

The move is likely to have far-reaching impact in stabilizing this war-torn southern African nation, which formerly was known as Rhodesia.

"Now there can no longer be an all-out-clash" between factions loyal to Prime Minister Robert Mugabe and Joshua Nkomo, his former guerrilla rival, a Westgern diplomat said. He called the completion of the disarmament process one of the most significant achievements since independence 13 months ago in winding down the military aftermath of seven years of guerrilla war.

The hostile guerrilla groups clashed in November and February in the southwest of the country, killing about 400 people, including many civilians.

There are still fears, however, that many of the former guerrillas have access to several thousand weapons stashed in the countryside. Others, refusing to be disarmed, have left their camps and have taken up a life of crime, a problem that could take years to resolve.

The caches, however, are a far cry from the huge supplies of armaments that almost 20,000 former guerrillas from both sides had available until recently. Nkomo's forces, the major threat to Mugabe's government, had tanks, armored vehicles, artillery and antiaircraft missiles.

Emmerson Mnangagwa, the military chief who announced the completion of the process, said in a telephone interview that about 18,000 men had been disarmed in seven camps around the country. He ordered the newly integrated national Army, made up of troops from the former Rhodesian forces plus those loyal to Mugabe and Nkomo, to carry out the disarmament three months ago, shortly after the February violence.

At the time, few people though the process would go so smoothly, quickly and without major violence by Nkomo's forces, who are annoyed at his party's low-level role in government.

In the only serious incident, three national Army soldiers were ambushed and killed by dissident Nkomo followers in March.

"I didn't think it would be achieved so quickly and without resistance," said a white official who previously served in sensitive positions in the illegal white government of Ian Smith.

He quickly added, however, "I have no confidence that this is the end of the problem of weaponry. . . . It doesn't mean the country is free of weapon-toting louts."

Mnangagwa said that Nkomo's 4,000 troops at Gwai River near Victoria Falls had been the last to be disarmed, with the process completed yesterday. That had been the touchiest camp because the former guerrillas had considerable heavy armaments, which were removed earlier this month.

Each camp is now left with just a few armed sentries, Mnangagwa said. No computation has been made yet of the number of weapons confiscated for the national Army, but they must be tens of thousands.

Ironically, the February violence, which centered around the black township of Entumbane in Bulawayo, speeded the disarmament process. About 300 people were killed in the fighting, which temporarily set back prospects for foreign investment. An angry Mugabe ordered the disarmament and told "all who challenge the authority of my government" that "I am determined to descend on them with a hammer."

Completion of the disarmament does not end Zimbabwe's military difficulties. The key problem is the integration of the two former guerrilla armies and the former Rhodesian security forces into a unified national Army.

Mnangagwa estimated that the total number of armed forces in the three groups, including guerrillas still being trained outside the country, is 65,000. Upward of 30,000 former guerrillas have been integrated with about 5,000 of the security forces.