SANTIAGO, Chile (AP) _ Military leaders said Wednesday they should not be held responsible for atrocities following a 1973 coup, but the country's Roman Catholic bishops urged the courts to determine guilt.

The clash over past human rights abuses intensified last week with the discovery of at least 20 well-preserved bodies in a mass grave in the northern fishing town of Pisagua, used as a detention camp for anti-government leftists in late 1973 and early 1974.

An Interior Ministry subsecretary, Belisario Velasco, said Wednesday that of the 20 bodies, 17 had bullet wounds, two were mutilated and one was beheaded. He said 15 bodies have been identified and their remains will be handed over to relatives.

Former military ruler Augusto Pinochet led the Sept. 11, 1973, coup that ousted an elected leftist government during a period of political and economic upheaval. His 16-year authoritarian rule was stained by charges of widespread rights abuses.

Pinochet handed over the presidency to an elected successor in March, but retains command of the 60,000-member military.

Pinochet sat in the front row, his face grim and brow lowered, when an army declaration was read at a gathering of the generals' corps Wednesday.

''Looking at things from the perspective of the peace we now enjoy, it may appear that the military reaction was exaggerated,'' it said. ''But this overlooks the fact that Sept. 11, 1973, was a military operation, that is a war action.''

It said Chile was being torn apart by ''an internal war, provoked by foreign ideologies.''

''War is never bloodless, and always brings pains, hates, injustices and inhumanities,'' the army statement continued. ''Thus we demand respect for our institution and for those who carried out in our ranks the tough chores of war.''

While in power, Pinochet decreed an amnesty for all rights abuse that occurred before March 1978.

A statement issued by Chile's bishops, released at almost the same hour as the army's, said that trying to elude responsibility for atrocities attempted to ''justify the unjustifible.''

''It will be the job of the justice system to clear up events and determine guilt,'' the bishops said. ''The country needs to know what happened.''

They also said anyone with information on the whereabouts of missing victims should step forward. At least 700 people disappeared during the wave of political repression that followed the coup, according to rights groups.

President Patricio Aylwin has created a special commission to investigate and report on the rights violations that occurred during Pinochet's rule. The army has expressed fears of a political witch hunt.