Armored infantry units of the Iranian Imperial Guard early today crushed a rebellion by air force recruits sympathetic to revolutionary leader Ayatollah Ruhollah Khomeini, government sources said.

The clash occurred at the Doshen Tappeh Air Base east of Tehran.

One recruit, interviewed this morning, said 20 recruits were killed during the fighting.But there were no officialfigures for casualties and officers on duty at the gate of the base and government spokesman would not confirm that there were any deaths.

The army put a cloak of secrecy over the incident, but a government source close to the military said tanks and armored personnel carriers were used to put down the rebellion.

The source said the incident began when a group of air force recruits held a demonstration in support of Khomeini and refused to disperse when ordered to by military police. The base commander summoned help from a nearby army unit, which "acted severely," the source said.

Residents of the area reported hearing extensive small-arms fire. Some residents reportedly went into the streets in an attempt to intervene on behalf of the dissident airmen, and others were said to have gone to the nearby former girls' school that serves as Khomeini's headquarters.

As the overnight curfew was lifted at 5 a.m. today, there were no tanks left. Nearly 200 people gathered in front of the gate to the base to protest the shooting and government troops shot into the air to disperse the crowd.

[The troops later opened fire on the crowd, killing at least one and injuring seven, according to news service reports. Gunfire was also reported outside Khomeini's headquarters.]

The only evidence of the violence was debris from burned barricades set in the street by area residents in support of the recruits in order to detain the army troops.

The airbase, near the sprawling Farahbad racetrack, has been the scene of previous antishah demonstrations by recruits.

The incident represents the most serious report yet in what appears to be a slow disintegration of military unity.

There have been growing fears of a complete split in the armed forces because of mounting pressure from Khomeini for soldiers and officers to stop "obeying the dictatorship." A substantial number of servicemen, including air force personnel, took part in pro-Khomeini marches in Tehran this week, and scores of air force technicians have been arrested at three Iranian bases for demonstrating in favor of Khomeini's proposed Islamic republic.

Of all the military branches, the air force has displayed the least unity in the face of Khomeini's Islamic-inspired revolution.

Yesterday, Medhi Bazargan, designated by religious opposition leader Khomeini to head a provisional "revolutionary" government, criticized members of the armed forces who remain loyal to the shah and the government of Prime Minister Shahpour Bakhtiar. He also announced a six-point program for the transition to an Islamis republic and called for a strike until the incumbent administration resigns.

Bazargan conceded however, that resistence to the proposed republic by Iran's military leaders posed "some obstacles" and he warned senior generals not to incur popular wrath and the "revenge of God" by reacting against his government.

Speaking at Tehran University to a large crowd estimated by the Tehran radio to number about 100,000, Bazargan was alternately critical and conciliatory towards the armed forces and Bakhtiar.

Diplomats said Bazargan's main aim was apparently to encourage Bakhtiar and the military to sever their links with the monarchy and avoid a potentially bloody clash.

Barargan appeared to be taking a softer line than Khomeini, whose immediate entourage has been urging him to act swiftly to forcibly take over government ministries and overthrow the last vestiges of the monarchy.

Bazargan has expressed concern about military reaction if this were done, and he has adopted a cautious policy of trying to leave Bakhtiar and the army an opportunity to retreat gracefully from their support for the monarchy.

Bazargan stopped short of calling for his supporters to take over government ministries to force the present administration -- already paralyzed by bureaucratic work stoppages -- out of office. But aides at the speech said privately he was under some pressure from hard-line Khomeini supporters to do so. They said Bazargan favored a more cautious approach.

A close associate of Bazargan's said that despite having been made provisional premier by Khomeini, he was "absolutely free to choose his own Cabinet."

The aide added, "Bazargan is not a person to be manipulated by anyone, including Ayatollah Khomeini. If he felt he did not have complete freedon, he would resign."

Diplomatic sources said, however, that while they did not question the nationalist leader's integrity, they doubted he could function independently of the powerful 78-year-old ayatollah.

While Bazargan was making his first public appearance since Khomeini named him premier of the provisional government, about 15,000 supporters of the Bakhtiar government held a rally at a stadium outside the city. They called for "full implementation of the constitution" and support for the army, a statement said.

Authorities reported some clashes between rival supporters of Khomeini and Bakhtiar but there was no mention of casualties.

A Belgian camera crew reported seeing a truckload of soldiers arrive to stop a brawl between rival groups. Instead of separating the factions, one group of soldiers joined the pro-Khomeini crowd and shouted, "Death to the shah," while another group teamed up with the Bakhtiar supporters. Finally, the Belgians said, the commander ordered his men back to their trucks.

In a 90-minute speech punctuated frequently by cheers of approval and chants of "God is great, Khomeini is our leader," Bazargan outlined the following program:

The resignation of Premier Bakhtiar and transfer of power to Bazargan's provisional government.

The reconstruction of the country's shattered economy.

Parliamentary elections.

The installation of a new government.

Elections for a constituent assembly to draft a new constitution.

A national referendum, subject to international supervision, on whether Iran should be a monarchy or a republic.

The last two points appeared to be at odds with positions previously taken by Khomeini.

Diplomats said it was clear, however, that if Khomeini's provisional government took over without provoking a military coup, the transition to an Islamic republic would be a foregone conclusion.

Speaking in front of a campus mosque, Bazargan did not announce his Cabinet as many of his supporters had expected. Nor did he describe any specific policies. He said the "revolutionary government" would be introduced "very soon," and indicated that the delay was because of military opposition.

Bazargan said many soldiers and "top generals" are not opposed to him and "do not want to interfere in politics." He added: "But we have some obstacles. There remain certain generals who do not agree with us. We have discussed the situation with them, and they say they have sworn to uphold the present constitution. That is their problem and they must solve it."

Iran's current 1906 constitution considers the monarchy an inviolable principle.

Bazargan, 72, a longtime opponent of the shah, says the army should stop "obeying the dictatorship" and "serving foreign interests."

He said he had told the generals, "the king will never come back to this country, and you [the military] will never have the same power as before."

Addressing Bakhtiar as "my dear Shahpour," Bazargan praised some of the prime minister's policies, such as releasing political prisoners.

"Our only criticism is that he is working under the shah's authority," Bazargan said. "The constitution we believe in is not much different from Bakhtiars. They only difference is that we don't believe in the monarchy."

Referring to Iran's economic problems, Bazargan warned Iranians not to expect "rapid improvement" under as Islamic republic. "I am riding a very weak donkey," he said.