A massive government show of armed force and opposition orders to avoid illegal public demonstrations combined yesterday to prevent yet another of the periodic major outbreaks of violence that have shaken Iran since January.

By nightfall only a few widely separated and unconfirmed incidents - involving perhaps as many as 10 dead - had been reported on what observers just days ago had feared might be the most deadly confrontation to date.

Thousands of soldiers patrolled Tehran streets in armored personnel carriers, machine-gun mounted Jeeps, light tanks and trucks.

But observers suggested that the relative calm was due in large part to calls by the Shute Moslem and National Front opposition specifically asking Iranians not to demonstrate in commenoration of the hundreds slain in Tehran's Jaleh Square on Sept. 8.

From his temporary home outside Paris, exiled Ayatollah Ruhollah Khomeiny, leader of the religious forces opposed to Shah Mohammed Reza Pahlan, issued no specific instructions other than to call for a day of mourning.

Analysts believed the major opposition leaders purposely played down the 40 day Shute Moslem mourning anniversary for fear the government would seize on any major violence to install a military government.

After the September violence, Prime Minister Jaafer Sharif-Emami's government ordered martial law imposed for six months in Tehran and 11 major provincial cities, but sporadic violence has continued unabated in smaller centers.

Despite the show of force, most Tehran shops were closed. Even in prosperous north Tehran, the only shops open were bakeries, groceries, pharmacies and banks, which kept their Iron grill prudently half closed.

Shuttered tight was the sprawling central bazaar. The economic and political heart of conservative and religious life in Tehran. Also quiet was the focus of leftist opposition - the various university areas in the capital.

Reporters who visited the capital's only cemetery - where many of the September victims were buried - said mourners paid their respect to the dead as nervous troops looked on.

Despite the relative calm, not even government supporters suggested that the Shah had turned the corner on what is now universailly recognized as his most serious trial in a quarter century.

Seemingly endless strikes for higher wages and their inflationary effect, sufficed to undermine any such illusions.

The unconfirmed reports of violence involved three dead and 40 wounded in west Tehran and seven killed in two widely separated incidents in the provinces.

In a related development, English language newspapers in Iran ended a four-day strike over the weekend after they were freed from a censorship order under a written agreement Saturday.