Agents of the Iranian secret police, SAVAK, intensified a crackdown on Moslem radicals and other anti-shah activists yesterday, arresting or issuing warrants for scores of religious leaders, journalists and other suspected subversives.

The embattled government of Shah Mohammed Reza Pahlavi also stepped up its campaign against former officials and senior civil servants as part of an anticorruption drive intended to neutralize public discontent over malfeasance and favoritism.

Among the alleged subversives arrested was Moslem Sheikh Yahya Nasiri Nouri, a prominent Shiite clergyman who was accused of plotting against the security of the state.

The government said it raided Nouri's Tehran home and found evidence of plots to commit arson and destroy public property. Official sources said, however, that there apparently was no evidence that Nouri was involved in the theater fire in Abadan last month that killed more than 400 persons.

Another well-known Moslem leader arrested was Mohammed Mofateh, who made an antigovernment speech Monday in north Tehran on the eve of a peaceful demonstration by anti-shah activists.

Sources said at least 20 mullahs, Moslem religious leaders, have gone underground since Saturday's bloody clashes between protesters and Iranian army troops.

Among the journalists arrested were three reporters from the newspaper Kayhan, one of Tehran's largest.

The secret police were also reported to have closed the office of the Iranian Association for the Defense of Liberty and Human Rights following the arrest of the president of its executive committee, Mehdi Dazargan, 73. Dazargan was president of the National Iranian Oil Co. when it was nationalized in the early 1950s. Rahmatollah Moghaddam Maraghei, a committee alternate, was also reported arrested.

Nasser Minachi, a member of the committee, told reporters yesterday he had been ordered to present himself to the authorities and that he was moving from house to house to avoid arrest.

He said armed agents of SAVAK moved into the his home, removed the phone and were holding his wife and daughter under house arrest.

Minachi said he had been in the United States for two months until Friday. "What case do they have against me? SAVAK men are sleeping and eating at my house," he said.

There was some evidence of resentment here among dissidents over President Carter's telephone call Sunday to the shah reaffirming the United States' friendly relationship with Iran and expressing the hope that Iran's political liberalization program will continue.

Some wall posters denounced the shah and "his servant Carter," and members of opposition groups said they felt betrayed by the president.

"The people think Carter approved the killing. They suppose Carter was protecting the shah. We know Carter has been trying to extend human rights to Soviet Union but in Iran he is not ready to push the government," said Minachi.

Meanwhile, handbills were being circulated containing a statement attributed to Ruhollah Khomeini, the radical Moslem leader who is in exile in Iraq. Khomeini called for further resistance by the people and desertion by army troops.

He asked soldiers to "join other brothers who deserted you and proved their support of the nation and attacked the enemy," an apparent reference to claims by purported eyewitnesses that in Friday's clash an infantryman turned his rifle on an officer, shot him and then killed himself.

The government continued to put the death toll in Friday's demonstration at less than 100 although dissidents insisted that many times that number actually died by rifle and machine gun fire.

Signs painted on walls claimed 1,500 dead, and one protest group alleged that 3,798 had been accounted for by noon Sunday, including 840 counted at just three Tehran hospitals.

A U.S. Embassy source, citing reports from opposition leaders, dismissed the government accounting as understated, and said 300 to 500 seemed more realistic.

Immediately after the shootings, eyewitnesses estimated 200 killed, but antigovernment leaders began revising the figures upwards after gravediggers at south Tehran's main cemetery began reporting that there were not enough plots to bury all the victims.

In the lower house of parliament, deputies began a debate on a motion of confidence in the government's modernization program, which ranges from strengthening the status of women to redistributing land. It triggered the protests by fundamentalist Moslem leaders.

Two deputies spoke against the program, charging that in presenting it Prime Minister Jaafar Sharif-Emami was responsible for Friday's violence.

Moshen Pezeshkpour, leader of the ultranationist Pan-Iranist Party, assailed what he termed a "totalitarian, bureaucratic clique" at the root of public dissatisfaction here.

"The people want justice instead of tyranny," Pezeshkpour said in a speech punctuated by catcalls from hecklers, one of whom shouted, "Well, without martial law, blood would still be flowing."

Speaking for the government, Justice Minister Mohammad Baheri said, "The people of Iran will never accept communism but [the protestors] shouted slogans and became tools of Marxists. But we have broken them."

State-owned Iranian television broadcast the debate nationwide including the opposition arguments. This was in sharp contrast to the conspicuous absence in government-controlled or pro-government media of substantive news of the ongoing tension within the anti-government groups.

Although several other deputies have registered to speak against the government program, observers expect only a dozen of the 365 members will vote against the motion later in the week.