The only sure things are the fear and the physical damage -- the burned-out hotel, the countless broken window panes, the debris of rudimentary roadblocks, the gutted pharmacies, liquor stores and hundreds of other shops and dwellings.

They bear witness that the swirl of violence which steadily has engulfed one Iranian locality after another in the past year has reached this manufacturing and garrison city of 200,000 people located 85 miles west of Tehran.

Once again the violence appeared to bear the now standard hallmarks of opposition mob rampage followed by army reprisal on a major scale.

Down winding, narrow streets, in the old part of town, three ayatollahs, or Shiite Moslem religious leaders, received visitors in their hiding place, convinced that the army and SAVAK, the secret police, are seeking to arrest them.

On the other side of town, stands a modern, bleak army garrison where Brig. Gen. Nematollah Motamedi, military governor and 16th Armored Division commander, has just printed up 10,000 copies of a long proclamation defending his troops and calling for cooperation with the population.

To cynics the printed proclamation is an unofficial admission that the army went overboard, a sentiment opposition sources played on in stressing that a high-ranking general recently arrived from Tehran with orders to restrain the local garrison.

The city is clearly in the hands of the army. Its tanks control key crossroads. Occasionally a soldier will fire off a single round just to remind the population who has the upper hand.

Still, walls are plastered with pictures of Ayatollah Ruhollah Khomeini, the Paris-based religious leader who has come to symbolize the struggle to overthrow Shah Mohammad Reza Pahlavi.

Color portraits of the shah and Crown Prince Reza festoon army tanks.

The trouble between the opposing forces came in two successive waves starting a week ago Wednesday.

Answers to such questions as who started the violence and how many people were killed before it finally ended -- 12 according to the government, about 200 say the opposition -- remain unclear to outsiders. They are matters of unshakeable conviction to the rival protagonists.

According to hospital workers, trouble began when three men were killed Dec. 27 by troops during an demonstration against the shah of the kind that has become commonplace throughout the country.

The hospital workers said nearly 120 people were killed the next day when troops opened fire on 20,000 demonstrators who had gathered at the cemetery to pay their last respects to the three who were slain.

The same day an army truck was said to have intentionally sideswiped a line of people outside a gasoline station, crushing more than a dozen children to death.

Government sources laughed at these assertions -- as well as charges that army helicopter gunships had fired on the crowd.

The sources insisted that outside Communist agitators had worked up the crowd to "terrible actions" of arson and looting against banks, liquor shops and stores that turned the south and west of the city into a "hell of fire and ashes" and caused millions of dollars in damage.

Only seven rioters were killed, the government sources added.

The burning continued the next day, but opposition sources denied that the crowd on either day was guilty of any destruction, despite the still visible presence of primitive barricades in the streets which seem to suggest otherwise.

Hospital sources acknowledge that few casualties have been brought to their attention.

"The wounded are afraid soldiers will burst in and drag them off for interrogation or worse so they prefer either not to come here or to leave quickly," a staffer said.

As for the dead, the religious leaders in hiding said in an interview they are convinced the army took away the bodies and buried them in outlying villages.

Many other dead and wounded were simply taken to their homes to avoid army detection and doctors expressed fears that some had died for lack of medical attention.

A spokesman for the religious leaders insisted, "We think every house in this town has its wounded or its dead."

The religious leaders insisted that they had preached, "We are not at war with the military. We are at war with the regime." They invoked Khomeini's name to stress that both the property and lives of military men and their families were to be respected.

Government sources disagreed. They insisted that the religious leadership was manipulated by "Communist terrorists" determined to launch attacks against all military personnel.

They said they had proof that photographs of various soldiers and officers were on display in Qazvin mosques and agitators had asked, "Who is going to kill this one or that one?"

They cited the case of a lieutenant who they said survived an attack by a mob of more than 100 men who broke into his home, shot him four times and stabbed him in 22 places. His 3-month-old child was almost strangled before his wife gave in to the mob's demand and handed over his service revolver, the government sources said.

Saturday and Sunday were calm, but each side accused the other of plotting. The religious leaders told their faithful that Gen. Motamedi was preparing a plan. The government side complained that noncommissioned officers living on the city's back streets were threatened by agitators.

Monday, New Year's Day, at 3:30 p.m., the religious leaders said they had received insulting telephone calls, a harbinger of the rampage to come.

Abruptly at 4 p.m., opposition sources said, the army and SAVAK attacked with troops, tanks, helicopters and armored personnel carriers. They burned shops, broke windows and looted and burned homes.

Two hospitalized men interviewed said they had been shot Monday without warning while out buying bread and other food.

"At the very moment we and the mosque were telling the people that the soldiers were our brothers," a religious leader said, "SAVAK has caused all the trouble. It wants to destroy the country like what happened in Lebanon and split us between right and left."

Government sources conceded privately that the soldiers "were crazy" after "so much provocation" and had "cleaned out a mosque" and "crushed some cars bearing Khomeini's pictures."

Both government sources denied that similar punitive actions were responsible for the extensive fire damage to the house of a prominent doctor, Gholam Hussein Dafteri. The government sources accused him of being a Communist, although hospital workers said he was the local leader of the National Front opposition coalition.

Dafteri and three other doctors fled for their lives, hospital workers said.

"No more Communists here -- they've all run away," a government source said, with undisguised satisfaction.

Also sacked, according to opposition sources, were the homes of several religious leaders and the cars of several doctors.

Government sources said the army had sealed off Qazvin for 24 hours on Monday and Tuesday. The government said it wanted to prevent more agitators from arriving with the convoys of food and medical supplies dispatched by the opposition.

Opposition reaction was less charitable -- especially in view of what it called the desperate need for medicine.