The shadowy revolutionary authorities now ruling Iran continued a bloody purge of former associates of the ousted shah today amid increasing digust among many middle-class and educated Iranians at the image being created abroad by the summary executions.

There is still no end in sight to the purge, which has taken the lives of 73 former officials so far, and the revolutionary authorities seem to be running out of former officials to accuse of specific "crimes against the people." As a result, the secret trials now are focusing on past political activities.

Despite the growing concern of many in the middle class, it appears that Ayatollah Uhollah Kohmeini, the religious power behind the government of Prime Minister Mehdi Bazargan, still speaks for most Iranians.

Khomeini, in a television address April 1, clearly stated his backing for the authoritarian system of justice that has produced the death sentences.

"There is no reason why a criminal should be tried in the first place," Khomeini said, referring to officials who he said had been "executioners" along with the shah.

"Human rights dictate that we should have killed the executioners right from the first day, because they were criminals and it was clear they were criminals. It is the accused whose case should be heard, whose claims should be investigated, not the criminals . . .

"All one need do with criminals is to establish their identity, and once this has been established, they should be killed straightaway."

Khomeini added that he was saddened that (we are afriad lest something should be said in the Western press about us."

He sharply attacked foreign human rights organizations for complaining about his court procedures, saying that many of these were the same people who, along with the United States, supported "the miserable shah."

Early today, Lt. Gen. Amir Hosseun Rabii, former air force commander, and Lt. Gen Ali Mohammed Khajehnoori, former chief of operations and training on the shah's general staff, were gunned down by firing squads here, along with former labor minister Manouchehr Azmoun and a Tehran policeman.

Five other men, all policemen or agents of the disbanded secret police, SAVAK, were executed later in the day in Iran's southern oil-producing regioh after being convicted by provincial revolutionary courts.

[In a first sign of leniency, the Associated Press reported, the Tribunals issued a one-year sentence to an alledged torturer. Until now, all announced punishments have been death sentences.]

The shootings brought the number of former officials executed since the new government came to power in February to 73. Twenty-four have been killed in the past four days, including former prime minister Amir Abbas Hoveyda. He was machine-gunned by an executioner at Tehran's Oasr Prison Saturday after being convicted on 16 diverse charges including "participation" in unspecified murders, "corruption on earth" and "active membership in the Freemasons."

The secret trials and death sentences hastily carried out by mysterious revolutionary tribunals made up largely of mullahs and acting under the authority of Khomeini-are putting the government of Bazargan in an increasingly embarrassing and difficult position.

Bazargan, a prominent human rights activist before Khomeini appointed him premier, threatened last month to resign ove the executions and the dominant role of Khomeini's ruling "ommittee."

At the Bazargan government's insistence, the revolutionary trials and executions were suspended last month while new rules for the rpoceedings were being drawn up.

The regualtions called for open trials, for defendants to be informed of charges against them befroe they go to court and for the presence of an official government representative.

The trials nonetheless remain effectively closed to the public, defendants still have not been permitted defense attorneys and there is no appeal.

Prominent politicians awaiting trial include former froeign ministers Abbas Ali Khalatbari, 67, and Ali Ardalan 78, and former parliamentary speaker Abdollah Riazi.

Before his execution early today, Rabii criticized the shah he once served with fierce loyalty.

"I'm unhappy that in ignorance I was Obeying someone whom I found to be a foolish man," he said.

Ironically, Rabii was one of a group of key officers who wanted to abandon the shah even before he flew into exile Jan. 16.