Afghan dissidents are undergoing guerrilla training at a base near here in a bid to intensify armed opposition to the Soviet-backed government in Kabul.

The guerrillas, linked to Islamic-based Afghan political parties, are recelving at least a measure of support from Pakistani authorities, although the government in Islamabad has denied that Afghan refugees are being allowed to train as guerrillas at a base 12 miles north of here.

There have been several reports of conflicts between the government of Afghan Prime Minister Mohammed Nur Taraki and tribal forces whose homelands are in the Afghan-Pakistani border region. There also have been reports of clashes near the capital, Kabul.

Jamiat-i-Islami, one of the two Afghan religious parties fielding apposition forces, has reported a number of air raids against villages sympathetic to rebel forces.

Afghans under the tutelage of Hizb-i-Islam, a fundamentalist Afghan Islamic party, are being trained at a former Pakistan military base north of here, according to a former major in the Afghan Army inrterviewed by three journalists earlier this week.

The camp, freshly painted,still contains some Pakistani Army vehicles and is under the guard of Pakistani soldiers. The Pakistanis, therefore, are clearly aware of any activity on the base.

The major, who asked not to be identified because his family is still inside Afghanistan, said he fled the country in September, when about 40 army officers were accused of plotting a coup against the Taraki government.

"All the people in this camp have vounteered to fight," he said. "When they go depends on the Central Committee of the party. We have some weapons here -- sten [hand-hald machine] guns and semiautomatic rifles -- and I take training.

"We are training them to be familiar with all the weapons, and in guerrilla warfare. All these people are well-educated. Some were students at Kabul University. Some were teachers, some engineers. This is a special course for them. They will be the officers of the future.

"I have divided them into six groups. Some are ready now to go and fight with their own weapons, but they still need to be familiarized with other weapons.

In all, the major said, 2,000 men were being trained in various camps inside Pakistan.

The guerrillas say some of their arms and ammunition have been captured from the Afghan Army, but officials of the Hizb-i-Islami in Peshawar said they had spent almost $800,000 on arms.

The Pakistani government has officially denied that the base near Peshawar is being used for training Afghan guerrillas and has said that the Pakistan government "will not allow" guerrilla training to take place.

"Pakistan's policy toward Afghanistan remains one of good neighborliness and respect for the painciple of noninterference into its internal affairs," the government said in a statement.

"The camp is guarded by the local militia. The militia also ensures that the inmates do not indulge in any objectionable activity, including guerrilla training."

The Pakistanis say the Afghans in the camp are refugee families who were moved from Peshawar following clashes between Afghans who had settled there after fleeing their homeland.

The journalists visiting the camp this week saw no women there, however, although there were said to be two or three and a few children. The 270 men billeted at the Warsack camp were almost all young.

Pakistan is in a dilemma over the Afghanistan situation. Troubled by the upheaval in Iran and the pro-Soviet tilt in Kabul, the Pakistanis nevertheless are seeking to stay on good terms with their neighbors. Internally, however, Pakistan has problems of its own with fundamentalist Moslem organizations demanding that steps be taken against the Taraki government.

In any case, there is little Pakistan can do to prevent refugees and dissidents from organizing guerrilla groups since much of the activity takes place in the tribal areas on the border where Pakistan has little jurisdicion.

There is no evidence so far that Pakistan is arming the dissidents or actively assisting with their training. Hizb-i-Islami representatives say equipment they are getting comes from party supporters. They were critical of Pakistani efforts to help the 32,000 refugees they say have poured across the border since Taraki came to power.