The leader of Lebanon's powerful Shiite Moslem Amal militia threatened today to launch attacks across the border into Israel, possibly in conjunction with Palestinian guerrillas, if Israel maintains control of a security strip in southern Lebanon.

Nabih Berri, who is also Lebanon's justice minister and minister in charge of southern Lebanese affairs, said that although his militia has been fighting the Palestinians in the refugee camps here to prevent them from reestablishing themselves as a military force in the south, the two Arab adversaries could unite against the Israelis.

"If one inch of Lebanon remains occupied, this means that the entire country is under occupation," he said. "This will impose new alliances on us with the forces desirous of fighting Israel. We shall not at all falter in requesting support from Palestinian or non-Palestinian forces to attain our liberation."

Meanwhile, at the Shatila refugee camp, grief-stricken Palestinian mourners, many of them wailing above the sound of sniper fire in the background, gathered to identify 83 bodies before a mass burial supervised by the International Committee of the Red Cross. A Red Cross official said only 35 of the badly decomposed bodies could be identified.

Young Palestinian women screamed obscenities at Shiite relief teams who carried the bodies to the mass graves, The Associated Press reported. Women clutching handkerchiefs to their noses to ward off the stench of death scrambled on hands and knees among fly-covered bodies laid out under pine trees, trying to identify husbands, sons and other relatives.

Volunteers wearing gas masks sprinkled quicklime on the bodies, and a clergyman blessed the remains. Seven bodies were taken away by relatives, and the rest, wrapped in bloodstained burlap bags and plastic sheets, were placed in a walled tomb and a pit in the graveyard at Shatila.

(A Red Cross official said that the victims included four women and three children but that most were young men. The known casualty toll so far in the battle for the camps is 516 dead and 2,120 wounded.

Berri's remarks were in an interview published today in Al Haqiqa, a newspaper that speaks for the National Resistance Movement, an alliance of Arab militias that has carried on a guerrilla war against the Israeli occupation forces.

Berri's Amal militia has been locked in bitter combat with Palestinian fighters in the Sabra, Shatila and Burj al Barajinah refugee camps on the southern outskirts of Beirut since May 19. The Shiites say they are determined to prevent the Palestinians from reconstituting their fighting power and military force there and in southern Lebanon, a predominantly Shiite region.

The insistence of Antoine Lahad, a former Lebanese Army general now commanding the Israeli-supported South Lebanon Army, to keep his force in Jezzin, overlooking a cluster of Shiite villages in southern Lebanon, appears to have prompted Berri's threat, in the view of observers here.

Lahad has said his decision to keep his militia there is irreversible and he has threatened to clash with U.N. peace-keeping troops, whose zone slightly overlaps with the security belt, if he is prevented from filling positions vacated by the withdrawing Israeli Army.

Lebanese President Amin Gemayel summoned the ambassadors of the five permanent members of the U.N. Security Council yesterday to ask their support for pressing Israel to remove Lahad's forces from the border strip.