Islamic insurgents waging war against Soviet occupation forces in Afghanistan have developed a well-organized and widespread web of supporters within the Afghan Army and the Soviet-installed government in Kabul, a recent trip to the capital city revealed.

This clandestine network is composed in large part of small groups of officials in government ministries who have built up caches of arms and now are actively engaged in urban guerrilla warfare against Afghanistan's Marxist ruling party, the Afghan People's Democratic Party, and its Soviet supporters.

In addition, Afghan Army officers, who remain in the units of the ruling government but are loyal to the insurgents, secretly travel to the outskirts of Kabul to meet with rebel leaders, pass along intelligence, and return with messages and supplies.

After two months of traveling with one of the chief rebel factions, I was secretly transported into Kabul on July 10 by several of these Army officers for a six-day visit. Once there, I stayed in the homes of four government officials who belonged to the clandestine resistance.

Despite the danger, the officials were eager to tell of their armed resistance. One of them told me he was frustrated that while there were occasional reports from the provinces, no journalists ever came to Kabul to report what the resistance there is doing.

These urban guerrillas live a divided existence. All the men I stayed with are employed by one of the ministries during the day, but during the late afternoons and evenings their energy is expended precisely against the government that pays their salaries.

Keeping in mind the tight security precautions of the Soviets, the constant threat of very thorough and sudden house-to-house searches and the often numerous roadblocks that are set up, these antigovernment activities are not so simple.

The rebels said it was far more difficult to organize actions against the government in Kabul than outside the city and that the only resistance they were capable of was quick hit-and-run assassinations, which they claimed they had executed with increasing success.

During the last few months confirmed reports have reached the West of assassinations of People's Democratic Party members and Soviet personnel in Kabul. In recent weeks, for example, diplomatic sources have reported an attack on a Kabul radio station that was taken over by insurgents for a brief time, and the hit-and-run slaying of Soviet troops guarding a government building in the center of the capital.

In two houses, I was shown well-hidden arms caches -- mostly pistols and highly primitive explosives. Obtaining workable explosives is a problem for the small groups operating inside Kabul. One of my hosts told me that in comparison to one or two years ago, the clandestine groups are in a much stronger position. He said they can now rely on transport -- like a car or a motorbike -- while in the beginning they did everything on foot.

He added, however, that the explosives used by the groups usually do not work. The rebels are dependent on the party bases in Pakistan to provide them with better materials, but the insurgents have not been able to smuggle high-quality or sophisticated bombs into the city.

Although theirs may be a ragged form of urban guerrilla warfare, the organization and secrecy of the rebel units are of the highest order. None of the groups contains more than eight men, all have at least two arms caches at their disposal and no group, even when belonging to the same opposition party, knows the identities of the members of the other groups.

The events that led to my trip to Kabul began on the third morning after my arrival with an insurgent band in the Paghman region just to the northwest of Kabul. There, I awoke to find the room filled by what turned out to be officers of the Afghan Army.

It was a Friday, June 19, their day off, and, dressed in civilian clothes, the Army officers had made the 10-mile journey to see the man whom they secretly called their commander, Abdul Haq, a leader of the Younis Khalis rebel group and the man I had accompanied into Afghanistan more than a month earlier.

Although a prominent insurgent leader who commands 200 guerrillas in and around Kabul, Abdul is only 22 years old. Yet 14 officers, some of them old enough to be his father and all of them with the rank of captain or higher, sat attentively listening to his orders as I watched.

That evening the young Younis Khalis commander explained the positions of the officers to me. He said that he trusted some of the officers completely, for they were men who had had close contacts with the insurgent leaders for many years. Some of them, he claimed, had even fought alongside the rebels during nighttime attacks on Soviet Army posts.

Other officers, Abdul said, had only joined the resistance recently -- mostly due to the Soviet presence and what Abdul said was a realization that the Afghan Army is a thing of the past. These officers wanted to establish ties to the rebels in case they eventually took power, Abdul said.

The officers, having heard of Abdul's return to the area, had made the trip that day to hear what orders he had for them. Some also asked if they could openly join the rebels, but their request was refused. Abdul later explained that he considered the Army officers much more useful if they stayed in their positions. He said that they had passed along information about Soviet or Afghan troop movements or planned operations, and were capable of supplying ammunition to the rebels in the provinces.

It was the officers who proposed that I be smuggled into Kabul, and after Abdul agreed, they returned to Paghman four weeks later and took me to a house on the outskirts of the capital. The next morning, I was driven into the city.

The journey to the house in the outskirts, during which I was escorted by a group of eight rebels, entailed a roundabout three-hour walk made necessary by the brightly lit Soviet or Afghan Army posts that are spaced all around Kabul.

We arrived without being spotted, but the captain who escorted me, so relaxed when I arrived, was tense and hurried the following morning, visibly impatient to be off and get me to my next destination.

We stopped only once on the way into the city -- to pick up another officer, a colonel -- and then raced on our way again. Minutes later, as we turned off the unpaved, deeply rutted road and onto the wide asphalt boulevard, the city lay before us. For a moment the jittery air of the captain left him, and with pride in his voice and a dramatic sweep of the hand he said: "Kabul."

It was a memorable moment. For sitting in the back of an Afghan Army jeep, with the captain as chauffeur, I was being driven into the one supposedly impregnable bastion of communism in Afghanistan. This was the one place, even Western diplomatic sources admitted, where Soviet security was so tight that nearly all antigovernment resistance had been crushed.

Yet here I was to spend the next six days, being driven from one house to the other in the back of the Army jeep. I sat in the back of the jeep, with the Army officers around me, and thus avoided discovery. On three occasions during the week, we crossed mixed Soviet-Afghan Army checkpoints, but each time we were waved straight through.

The city was only just beginning to stir when I arrived; traffic was light and there was little if anything to see on the wide boulevards and streets we passed through.

But I noticed just how full and seemingly normal the city can be during the four other journeys I was to make in the Army jeep in the following six days. Because the dense traffic forced the Army officers to drive at a somewhat more reasonable pace, these trips gave me the chance to see something of the capital. Thus we drove past the carpet bazaar, a large whitewashed building that seemed as busy as ever -- despite the obvious lack of Western tourists. And we passed the deserted but seemingly permanent reviewing stand where President Babrak Karmal and other members of his government watched a military parade on April 27 of this year, the third anniversary of the communist takeover.

I noticed that while the Soviet soldiers openly carried their arms, the Afghans had none -- another sign of the distrust of anyone who is not a committed member of the People's Democratic Party of Afghanistan.

Apart from the checkpoints and the odd convoy of armored personnel carriers, the Soviet presence seemed hardly noticeable within the city proper. And it seemed that Kabul has witnessed a population explosion in the last few years. Hundreds of party members, knowing themselves to be unsafe in the countryside or in smaller towns, have sought refuge there, as have thousands from the villages in a wide area around Kabul.

By sheer necessity my impressions of the city were limited to those five car rides -- for I could not have ventured onto the streets without papers or knowledge of Pushtu, the predominant language. Some of my hosts spoke English and helped me communicate with those who did not.

Only once while in the city did I see direct evidence of the reported violence. That evening I was watching television in one of the homes when we heard three short bursts of submachine-gun fire from no more than two or three streets away.

A few minutes later, one of the men of the house burst into the room and, still out of breath, reported that a retired general and influential member of the ruling faction of the People's Democratic Party had been shot to death. It remained unclear who had killed him, although it seems that it was most probably done by members of another faction within the party.

Later that evening, the television program -- a Russian film over which Pushtu was awkwardly being dubbed by a studio announcer -- was interrupted by a news flash that confirmed Fateh Mohammed's death. The announcement called the incident a "disgusting act of murder by Zionist, Chinese, American imperialist CIA agents."