For the first time since an inconclusive offensive in July, the Soviet Union has deployed its ground forces extensively against Afghan rebels in fighting near the town of Paghman, nine miles north of Kabul, Western diplomatic sources reported here today.

A column of more than 200 Soviet tanks, armored personnel carriers and artillery pieces left the Afghan capital of Kabul for Paghman early last week, while Soviet Mig21 fighter bombers and helicopter gunships bombed and rocketed the town, the sources said.

The Soviet troops began to withdraw Saturday, according to reports from Kabul, but bombing raids and shelling by tanks and truck-mounted Katyusha rocket launchers continued.

The diplomatic sources said the new offensive, supported by Afghan government troops, appeared to be directed at civilian populations in areas where the Mujaheddin rebels have received support.

They said the attacks were in retaliation for the abduction late last month of 10 Soviet soldiers, including four officers.

The sources interpreted the new use of Soviet troops as a tacit admission that Afghan troops have failed to control the strategic area near the capital. After the July offensive, the Soviet-backed regime of Communist Party chief Babrak Karmal claimed that Paghman was "liberated" and that calm had been restored to the area.

The Kabul reports described the death toll of civilians as high and said survivors are still digging bodies out of the rubble. Heavy casualties were reported in one bombing raid on the principal bazaar in Paghman.

Heavy air attacks by low-flying Migs were also reported in the Shomali area just north of Kabul, on the road to the Salang Pass, diplomatic sources said. One town, Kalakan, was surrounded by tanks and shelled heavily, while Soviet gunships raked the ruins with rocket fire, the sources said.

"The bombing has united several bickering Mujaheddin groups," one source said.

A number of villages near Paghman sustained the heaviest bombing attacks since early July, according to the Kabul reports.

In the Panjsher Valley, rebel forces were said to have surrounded an Afghan Army garrison left behind when Soviet forces withdrew. On Oct. 3, the rebels reportedly captured 50 Afghan soldiers in one sneak attack.

The reports from Afghanistan said that although a majority of the civilians left the Panjsher for Kabul or Nanjahar, some have been filtering back in response to an appeal by Massoud, one of the leading Mujaheddin leaders. Diplomatic sources said the rebels in that area appear to be better equipped than they were in July and were making increasing use of shoulder-fired missiles.

Rebel sources claimed to have destroyed four Soviet armored vehicles Friday and to have downed two helicopter gunships the day before.

Diplomatic sources said that following heavy fighting last week in the Argan Deh Valley, Soviet troops surrounded one village and conducted house-to-house searches. The sources said the troops looted food supplies and dumped what was left in a pile and burned it. They also slaughtered cows and sheep, according to the reports.