Three rival Afghan resistance organizations, in a significant departure from their usual divisiveness, have collaborated in a precision ambush of a large Soviet and Afghan military convoy and seized a sizable supply of arms, according to Western diplomatic reports from Kabul.

The attack on April 1, one of several rebel offensives in the Shomali district between Kabul and the Hindukush mountain range in the last 10 days, was coordinated several days in advance on the basis of intelligence reports that the military convoy would pass through the Panjshir Valley, the diplomatic sources said today.

The three groups of the frequently fractious rebels that reportedly participated in the ambush were the Hezbe-e-Islami, the Jamiat-e-Islami and the Harakat-e-Enqelabi guerrilla units.

The ideologically diverse and frequently competitive rebel groups have been known to be divided in the past. The reports from Kabul said that none of the forces led by the rebel commander of the Panjshir Valley, Ahmed Shah Masoud, were involved in the attack.

According to the reports, the combined rebel force split the military convoy and surrounded a trailing column of armored Soviet and Afghan vehicles, killing and capturing an unspecified number of troops.

After the battle, which lasted into the night, the rebels eluded Soviet air strikes and escaped into the hills, the reports said.

Two days later, rebel forces reportedly attacked a Soviet Army force outside of Opian, near the Parwan provincial capital of Charikar, and destroyed at least five armored vehicles. Intense fighting was also reported in the town of Ghazni, between Kabul and Khandahar, and in Maidan Shahr, just south of the Afghan capital.

According to diplomatic reports from Kabul, Afghan rebel leader Sayed Mohammed Hassan Jaglan, principal commander of the moderate Hazarajat Provincial Revolutionary Council, who last year was reported to have made a nonaggression pact with the Soviet-backed regime headed by Babrak Karmal, has renewed his resistance activities.