The Afghan refugees are settlilng in. A miniature city of mud huts, the usual housing in Afghanistan, has sprung up here to replace what a few months ago was a rough collection of tents pitched privately owned fields.

Now this highly visible refugee settlement has taken on a sense of permanence. It has become a visible symbol to residents of the Northwest Frontier Province, who are becoming increasingly upset with the influx of Afghans, that the refugees appear here to stay.

"The people of the Frontier have been very tolerant, but our sympathies are wearing out," said one Peshawar resident who poured out a litany of complaints against the Afghans. His view was echoed by a dozen residents interviewed in Peshawar, the province capital.

He said the antirefugee feelings have intensified during the summer added that he feared open clashes could break out between the residents here and the Afghans have flooded over the border since a pro-Marxist regime seized power in a bloody coup in April 1978. The vast majority of the million Afghan refugees in this country are centered in the Northwest Frontier area.

Tensions increased, according to the Peshawar residents and international observers, as it became obvious to the Pakistanis that the refugees will not be able to return to Soviet-occupied Afghanistan any time soon.

While there have been no serious incidents between refugees and Pakistanis in the Frontier area, major clashes have been reported in the harsher, less hospitable desert areas of Baluchistan to the south, where another large group of refugees has settled.

One of the biggest clashes took place in the Baluchi town of Pishan, where more than 100,000 refugees have set up a string of tribal camps in the hot, dry and dusty land alongside the road. The fight there was sparked by exactly what is now going on in this villiage -- refugees moving out of the temporary tents and putting up mud huts on privately owned land.

The government of President Mohammed Zia ulHaq has played down this clash, but according to rreports reaching the Pakistan capital of Islambad at least four persons were killed and the Army had to be called in to keep order when a Baluchi landowner bulldozed down the mud huts that refugees had just erected on his property.

As an indication of how frayed tempers are in Baluchistan, two persons were reported killed in a battle that started when a refugee riding a motorcycle ran over a Balluchi child.

Tensions are exacerbated in Baluchistan by the extreme poverty of the area and the harshness of the land, which can barely support the 2.5 million people who live there.

The addition of the refugees has placed great strain on the little water available in that arid land. The more than 700,000 head of livestock broughtt in by the refugees is competing with the Baluchs' sheep for scarce grazing land.

The same problems are present in the Northwest Frontier, but so far the tensions have not erupted into violence, possiblly because the residents of that area and the refugees belong to the same great tribe, the Pushtoons, and in many cases, have extended family relations. In Baluchistan, while refugees are Pushtoons, many of the residents belong to the Balushi tribe.

Nonetheless, the tensions between Afghans and Pakistanis are not far below the surface around here. "The people are starting to feel the presures," said a Peshawar resident.

Some of the friction points are slight -- such as the increased automobile traffic in some sections of town and the invasion by Afghans of quiet neighborhoods. One man said an Afghan refugee family in a quiet residential section of Peshawar use a vacant lot as a toilet, and play their radios loudly day and night. People now lock their front gates, he said.

"Afghans are not the best of neighbors," he said. "I wish them health and happiness -- and that they go back to Afghanistan."

Beyond the personal irritants, there are major problems that the influx of 840,000 Afghans are creating for this rough and rocky land, which can only marginally support the people who already lived here.

Accustomed to using wood as cooking and heating fuel, the refugees have cut down most of the trees in the Dir district, in the extreme northern section of the Frontier Province. In the Hazarra district there have been scuffles beteen Afghans and residents over tree cutting and land rights.

"The Afghan is by definition an enemy of trees. He cannot see a tree standing," said one Frontier resident.

The two million head of livestock -- mostly sheep -- had what a United Nations High Commissioner for Refugees report termed "a miracle" lambing season this spring. But the great increase in the number of sheep, it said, "is likely to cause severe problems" of overgrazing during the coming winter months.

Moreover, the arrival of camels as pack animals is expected to further aggravate the grazing problems.

Since there is little publicly owned land in the Frontier territory, the arrival of the refugees is impinging on private property and long established grazing rights.

The refugees are not paying for use of grazing land. Often they were given permission to settle on a plot of land with the idea they would soon move on. Now, when the owners ask them to leave, they refuse because they have nowhere else to go.

The land here, lying beside the major highway connecting Peshawar 23 miles to the west and Islambad, formerly was used to grow reeds which were sold by villagers to a nearby paper mill.

Now that source of income is closed to people here. The Afghans, however, are making themselves at home on the land. They have even set up tea shops as social centers and tapped into the main power lines for electricity. According to one observer, they have not even planted gardens since the $5 a month each person gets, along with food supplied by the United Nations, is more than enough for them to live on.

Beyond that, many of the Afghan refugees were able to bring trucks and buses with them which they used in the transport business. Until last week, they were paying no road or route taxes, which the Pakistani truckers considered unfair.

Some refugees are taking low-paying construction jobs, and Pakistanis complaining that the refugees are able to work for less -- $20 a month instead of the going rate $30.

Pakistani security officials are concerned that the Soviets and the Afghan government that the Soviets and the Afghan government are infiltrating agents into this country with the refugees. A series of bombings this spring are widely believed to have been the work of Soviet agents and there have been unsubstantiated reports in Peshawar of antigovernment rumor-mongering.

One pamphlet appeared in Peshawar stating, "Pakistan will not be the base for the subersion of the Afghan revolution."

There was unsupported speculation in the Afghan capital of Kabul last month that the Soviets were behind the clashes in Baluchistan, but most observers in this country doubt it.

Nonetheless, the concerns are present. Pakistanis here fear the large number of refugees and the headquarters of Afghan rebel groups in Peshawar could spark retaliatory raids by Soviets troops posied across the Khyber Pass.

Despite the frictions and the potential for trouble, the acceptance by Pakistan of 1 million Afghan refugees has been remarkable achievement in that there have been no epidemics, no deaths from starvation.

There remains a reservoir of Islamic kinship that keeps residents here from ousting the refugees. One government worker, for example, went to a mosque for evening prayers last week and found a 13-year-old Afghan boy crying. The boy said he had fled his village after a Soviet bombing raid and did not know whether his family survived. The man took the boy into his home.

Yet there is still some suspicion. The man admitted he was not sure if the boy's story was true and he worried that the Afghan refugees might be a theif who would loot his house while he was at work.