The Afghanistan guerrillas left Peshawar, Pakistan, in a battered bus with blue and gold tassels streaming from its fenders, flowers painted on its roof and the faint smell of hashish drifting from its open windows.

Crammed inside the 40-seat bus were about 60 "mujaheddin" Moslem freedon fighters, together with sacks of military supplies gathered in Peshawar and Pakistan's notorious weapons production and trading center of Darrah.

The guerrillas were healed back to Afghanistan and their home valley of Derinur, a day's march west of the Kunar River. The supplies they carried would help them resist expected government attempts to regain control of their valley. They could now also conduct guerrilla operations against Soviet and Afghan Army units fighting in the region.

As in many villages of eastern Afghanistan, the people of Derinur took up a collection shortly after the Soviet invasion in late December. They elected a military commander and dispatched him to contact rebel groups in Peshawar for help.

Derinur's commander, Kabul University graduate Satar Hayat, came to Peshawar in late January with his men and a shopping list of desired weaponry.

Although he failed to get all 100 rifles and 50,000 rounds of ammunition that he had sought or the machine gun or rocket launcher on his list, Satar still considered the trip a success.

"I have spent my village's money wisely," he said.

But more importantly, he had established links with major Peshawar rebel group, the Jamiat Islami Afghanistan, which had added to his arms, ammunition and supplies, and extended the promise of more help in the future.

Now Satar and his band had joined one of the well-traveled rebel supply trails linking Peshawar with the major fighting areas of eastern Afghanistan. t

The routes are vital lifelines that help sustain guerrilla action against Soviet and Afghan Army units.

As with any group of soldiers on their way home, the mood was buoyant as the bus bumped along the rutted highway into the hills of Pakistan's frontier tribal areas.

Near the village of Kuda Khel, 40 miles northwest of Peshawar, the bus pulled into a dry river bed. There the supplies were unloaded and distributed for individuals to carry. As the rebels, aware of the importance of their guns, unwrapped their modest arsenal, the scene in the riverbed had the aura of Christmas.

New rifles, mainly locally produced copies of World War I vintage British Enfield .303s or Pakistani Army small-arms of the same caliber, were carefully inspected. Most had been purchased in Darrah.

An American-made Remington 1100 shotgun drew a cluster of admiring mujaheddin. According to Satar, about 60 weapons and 7,000 rounds of ammunition were brought in.

As rebels filled their bandoliers, empty bright blue ammunition boxes lettered "Interamrs, Alexandria, Va." soon littered the ground, mixed with the less distinctive packaging of a Czech manufacturer, Selliert and Bellot.

Nearly 50 American-made antitank mines, medical supplies from China and 980 pairs of boots were taken into the nearby village in preparation for the second leg of the trip.

This journey is along a rough dirt track through 20 miles of no-man's land that neither Afghanistan nor Pakistan has ever pretended to control. Inhabited mainly by nomads, the broad flat road for centuries was a favored camel train route.

However, since the Afghan insurgency campaign hit full swing last year, enterprising farmers on both sides of the border have converted their tractors into a thriving shuttle taxi service, charging rebels the equivalent of $16 to cart to Afghan villages as many men and supplies as they can pile on.

There, the farmers pick up tired refugees, fleeing the fighting in the Kunar valley, and for a similar fee, bring them back to Pakistan.

Perched atop ammunition boxes strapped to a tractor's backhoe, rebel commander Satar, 28, and eight others rode into Afghanistan and talked of confronting one of the world's biggest and best-equipped armies.

This night, the destination was the village of Zemarychena, a few miles inside Afghanistan. There, Afghans with similar loose links with the Jamiat Islami Afghanistan rebel group fed and sheltered elements of the supply force as they arrived.

The arrangement is typical of rebel supply routes throughout the eastern part of the country. Consequently, most guerrilla units carry neither food nor water, even on long trips.

The diet is almost always the same: unleavened bread, yogurt and tea. Sometimes rice and bits of meat or chicken are added if the occasion is special or the host generous.

The following afternoon, the rebels accompanied by nine donkeys carrying the heaviest supplies, hiked west into the hills.

The guerrillas pace of the column as it marched for 9 to 10 hours between breaks through the rugged mountain terrain attested to the uniform strength and endurance running through the rebel ranks.

Occasionally Satar would call halts for prayers, but only a few of the group prayed. Most sat and watched. Often the column halted briefly to talk with travelers coming from the opposite direction.

A column of mujaheddin making its way from Lagman Province to Peshawar for supplies reported that the way to Derinur was clear. Satar smiled and thanked the group for its news.

But on the trail, conversation rarely goes beyond the necessities. When asked with what organization the other rebel group was affiliated, Satar replied succinctly: "I didn't ask. That's politics and it can cause trouble."

By the late afternoon of the second day, the column had moved to within a few miles of the Kunar River. It had run out of cover and now waited for darkness to proceed. From a gorge carved out by one of the Kunar's many tributaries, rebels watched Soviet helicopter gunships flying up the valley and discussed the probable location of Afghan Army positions on the far bank of the river.

To reach Derinur meant crossing both the river and the main Soviet supply line.

The plan was simple. Wait for darkness, walk four hours south along the Kunar to a small village where a boatman is known to ferry rebel groups across the river at night for between 10 and 15 cents for each person.

Satar broke the group into three squads, but occasional loud talking and lighting of cigarettes exposed them to detection from any alert defenders. If toughness and dedication are Afghan rebel strong points, discipline is not.

At the boat crossing, the presence of another rebel group moving men and supplies across the river forced Satar's band to wait on the small strip of beach along the bank.

Around 4 a.m., Satar decided to postpone the crossing until the following night. Slowly, the group moved into a nearby village for shelter and to wait for the coming hours of daylight to pass.

The next evening, Satar and 15 others of his group clambered aboard the fragile raft, made of inflated animal skin and a thin wooden frame, and led the group toward the murky darkness of the enemy-held bank.

The crossing took barely five minutes. With the first crunching of gravel under the raft, the rebels scrambled off and moved quickly up the bank. This was the period of maximum danger in the four-day trip. After a few minutes the group reached the main paved road used by Soviet armored columns moving north up the valley.

Within 15 minutes the rebels were climbing into the hills and relative safety. During the next 6 hours, the column move its way in darkness up the lush Derinur Valley. Just before dawn, four days and countless miles from Peshawar, the rebels of Derinur reached home.