Wearied by Ayatollah Ruhollah Khomeini's Islamic revolution and the debilitating war with Iraq, Iranians are slipping across the Pakistani border in increasing numbers and thrusting a dual burden on Pakistan: a new influx of refugees and a potential source of irritation between the government of President Mohammed Zia ul-Haq and Iran.

While the numbers are small compared with the estimated 3 million Afghan refugees living in border camps in Pakistan, the fleeing Iranians are the vanguard of what could evolve into a large influx of asylum seekers disenchanted with the nearly six-year-old Islamic revolution, according to international social workers here, in Karachi and in the capital of Islamabad.

Because the Iranians keep a low profile in transit through this provincial capital of Baluchistan and the port city of Karachi, it is difficult to ascertain their exact numbers. The Office of the U.N. High Commissioner for Refugees has registered and accorded refugee status to only about 4,000, of whom 2,200 are still in Pakistan, but UNHCR officials said that only a small proportion of the refugees come to their attention. The majority remain hidden or leave Pakistan illegally for destinations in Europe and elsewhere in the West. "It is just the tip of the iceberg," said one U.N. official.

A local "fixer," who helps Iranians en route through this desert city to Karachi, said he has handled 5,000 to 6,000 refugees. He estimated that the figure represents 5 to 10 percent of the total.

Interviews with numerous Iranians here and in Karachi offer a profile of a typical refugee as young, middle class, educated and either openly sympathetic with the deposed monarchy or disillusioned with the revolution he once supported.

Many are of draft age and said they were fleeing Iran to avoid being sent to the front in the four-year war with Iraq. About half, U.N. officials said, belong to the Bahai religious sect, which has been persecuted by the Khomeini regime, and half are Moslems who call themselves political refugees.

For a fee that generally is 1 million rials (equivalent to $1,700 at the official exchange rate), they are guided on an arduous journey across the barren desert of eastern Iran and Pakistani Baluchistan, traveling four days or more on seldom-used trails by truck, jeep, motorcycles and even camels.

Using Zahedan, Iran, as a staging area, they cross the porous border at Koh-i-Taftan at night and drive 400 miles across Baluchistan to Quetta, where they rest for a day or two before making the final leg to Karachi.

There, crammed into several cheap hotels, they either seek refugee status from the Office of the U.N. High Commissioner or buy forged passports and fly to countries in Western Europe, where they seek political asylum.

Pakistan, already faced with unfriendly neighbors Afghanistan and India, appears reluctant to antagonize the Iranian government. As a result, it has refused to confer the refugee status on the Iranians that it has on waves of Afghan refugees since Soviet troops invaded Afghanistan in 1979.

Pakistani officials are reticent about the illegal Iranian influx, reluctant even to acknowledge the existence of the phenomenon, and have imposed what amounts to a news blackout.

Facing this reception here, and an increasing wariness on the part of immigration officials in the United States and elsewhere, the Iranians say they feel abandoned and adrift, forced to adapt from their comfortable middle-class surroundings to the spartan life of an urban refugee in Karachi.

"I dream of going to America. We all dream of going to America, but what can we do without a passport or a visa? Nobody wants us, and nobody is helping us," said Khalid, a 29-year-old carpet dealer from Isfahan who fled his home three months ago and is living here now.

All of the refugees interviewed agreed to talk only on the condition that their last names not be used, because, they said, they feared reprisals against family members in Iran.

Khalid, who left a wife and three children in Isfahan, said he supported the revolution for the first two years of Khomeini's rule and fought the Iraqi Army on the plains around Khorramshahr in 1980. But soon after, he said, he became disenchanted and embittered by the losses in the war.

"Khomeini said this is a jihad holy war . But in true Islam, this is not a jihad. A jihad is a war against infidels, not other Moslems," Khalid said.

Like many refugees interviewed, Khalid said he favored a return to a constitutional monarchy and a relaxation of the fundamentalist Islamic strictures imposed by Khomeini.

"You want to go pray? Then go pray. You want to go to a bar and drink, then go. I hope the shah's son comes back," Khalid said.

Repeatedly in interviews in the Oriental Restaurant here, a seedy gathering place for Iranians, refugees said they fled just before being drafted or because their credentials as revolutionaries and ardent Moslems were suspect and they were denied admission to universities. Some said they were under surveillance by the secret police or were being harassed by Revolutionary Guards.

Sitting in the Bloom Star Hotel in Karachi, Ghassan, 24, an urbane-looking former airline steward, said he fled Tehran two months ago after friends told him he was about to be arrested as a suspected counterrevolutionary.

Ghassan said that his father, a former agent of the shah's secret police, SAVAK, is in prison and that a sister was killed by Revolutionary Guards.

"I never supported the revolution. It was a revolution of uneducated beggars who got uniforms and guns and became powerful," said Ghassan. He added, "The shah was not that good, but his positives were slightly more than his negatives. Khomeini is worse. Just compare the number of people assassinated by these two regimes and you will agree to that."

Bahai refugees interviewed talked of constant persecution, relatives and friends executed, and fear of arrest, rather than of political discontent. Most of them have plans to immigrate to Australia or the United States, and U.N. refugee officials said Bahais were more readily accepted in those countries because of their lack of politicization and because of organizing efforts by Bahai relief groups.

Behroz, a 24-year-old Bahai from Isfahan, said he fled two weeks ago because his religion barred him from college and because several friends were executed. Traveling with three other Bahais, Behroz drove by pickup truck and then on two Soviet-made motorcycles from Isfahan to the border, where Iranian Baluchis dressed them in the traditional Baluchi garb and smuggled them into Pakistan.

Iranian and Pakistani Baluchis do a lucrative business smuggling refugees -- a trade that began to pick up when Turkish security forces were reported to have rounded up Iranian refugees and forced them back across Iran's western border last year.

One Iranian Baluchi smuggler, Jamshid, 25, said in an interview in Karachi that infiltrating the border is "like drinking water, it is so easy. I come in and go out, just like that."

Jamshid, who claimed to have smuggled former Iranian president Abol-Hassan Bani Sadr's wife out of Iran, proudly calls himself a refugee smuggler, "the best in Iran. My name is very popular. I can't remember how many I have taken out." Sitting in the Bloom Star Hotel's cafe with an armed bodyguard, Jamshid added, "I should go to Mexico. I could learn Spanish and make a lot of money."

Although refugees and Baluchi "fixers" said they were certain Khomeini's agents were watching them in Pakistan, Hamid Bassiri, the Iranian consul general here, said he was not aware that refugees were seeking asylum in Quetta and Karachi.

"There are international smugglers everywhere in the world, and they come and go," Bassiri said, referring to the Iranians' statements in the interviews.

When pressed on the question, he said, "We don't know anything about that. There are counterrevolutionaries, people who don't accept the present government. They can emigrate legally. We only know about those with official passports who come to us."

U.N. officials said they were in an uncomfortable dilemma because of the Iranians, caught between their mandate to assist all refugees and the delicate relationship with an uneasy Pakistani government. Moreover, increasing frustration of Iranian refugees who are unable to obtain visas to other countries has led to growing tension and at least three sit-ins at U.N. refugee offices in Pakistan.

Noting Pakistan's reluctance to antagonize Iran and acknowledging the widespread support of the Khomeini revolution in fervently Islamic Pakistan, one U.N. official said, "it is a sensitive issue. A draft dodger is not by definition a refugee. But we have noticed in the last two years growing fatigue in Iran with both the war and the revolution." The official asked not to be identified.