A police fusillade against a crowd of religious demonstrators here last week has sparked a series of strikes and disturbances throughout Iran and pitted the government against what is potentially its most formidable domestic [WORD ILLEGIBLE] the country's Moslem faithful.

Tension has continued to build over the Jan. 9 shooting, which left more than 70 dead by some counts, although the government says only six died. Today shopkeepers in the labyrinthine Tehran bazaar, where religious feelings traditionally run high, staged a strike to mourn the "barbaric massacre of innocent people," a statement said. The strike, in deliance of police threats to revoke shop licenses, was the first concerted protest from the bazaar since Shah Mohammed Reza Pahlavi exiled Iran's leading ayatollah - the top Moslem religious rank - 14 years ago for his political opposition.

Although no official proclamation has been made, Qom, considered a "holy city" because of its Shilte Moslem shrines, is effectively under martial law, according to Ayatollah Sayed Ghassem Shariatmadari, who is now the country's highest religious leader.

With a personal following of several million people and as the spiritual leader of Iran's Shiites, who make up 98 per cent of the 35 million population, Shariatmadari is one of the most powerful men in the country after the shah.

More than half the shops in the city, located 90 miles south of Tehran, are closed; riot police guard its mosques and theclogical college, and plainclothes agents keep the population of 250,000 under surveillance.

"We still don't know why the police fired on the people," Ayatollah Shariatmadari, 76, said yesterday in his first interview with foreign reporters. "There was nothing to provoke it."

He said a crowd of worshippers, estimated at more than 5,000, had just come out of a large mosque and started to march to the houses of the city's ayatollahs when police opened fire with pistols and submachine guns. It was the second day of peaceful demonstrations to protest an article in a government-controlled newspaper insulting the exiled leader, Ayatollah Ruholla Khomeini, QOM residents said. Khomeini now lives in Iraq but still has strong support in Iran.

According to Moslem prayer leaders in QOM, the shooting lasted for 2 1/2 hours, leading some observers to speculate that the police simply got carried away with what was supposed to be a strong-arm tactic to prevent further demonstrations.

Afterwards the police prevented citizens from donating blood to the wounded or visiting them in hospitals, and many are believed to have died there. QOM residents said. Some residents put the death toll at 200 to 300 - including many prayer leaders and theological students - and charged that authorities dumped truckloads of bodies into quicksand surrounding a nearby salt lake to keep the death toll a secret. This could not be confirmed, however.

As part of a massive campaign to counter public outrage, authorities bused thousands of Tehran factory workers and low-level government employees to Qom over the weekend to stage a pro-shah demonstration. Similar events have since been organized in other cities, and newspapers have denounced the clergy as reactionaries who want to return Iran to the stone age.

In a rare open letter to "believers," Shariatmadari condemned the shooting as "un-Islamic and inhumane," and added, "we are certain that Almight God shall in time punish those responsible." More than 20,000 copies of the handwritten letter have already been distributed throughout Iran, prayer leaders said.

The Aytollah emphatically denied the government version of the incident: That the demonstrations were to protest women's emancipation and land reform and that the crowd stoned police and attacked a precinct station. "That's an absolute lie," he said.

The Ayatollah , who has never been particularly outspoken politically before, called for a return to constitutional rule in Iran, where government is presently dominated by the shah.

"The government says we are reactionaries and backward," Shariatmadari said. "Well, if being backward means we want the constitutional laws to be respected, then we accept that definition."

The ayatollah sat cross-legged on a carpet as he answered questions from three foreign journalists at his QOM residence. Plump and white-bearded, with an air of serenity and a twinkle in his eye behind old-fashioned spectacles, he lacked the austere manner that one would usually associate with his black turban and long robes.

Shariatmadari said he could have ordered all the bazaars and mosques in Iran closed, sending thousands of people into the streets, but that this would only risk more shootings.

Although various towns have asked him to order strikes, he said, "I didn't give the order because we have no arms, no force, and people would just be killed."

For the time being, the authorities seem to have the situation under control, but prayer leaders say new protests could break out anytime.

"The people are still against the government," one said. "There will be more demonstrations, but we can't predict when."