Chile's Roman Catholic bishops have called for "serious revision" of the constitution introduced by President Augusto Pinochet, which prevents congressional elections until 1990 and could hold off a full presidential vote until 1997.

The 30-member Episcopal Conference also strongly criticized the courts' failure to deal with political violence which, it warned, "threatens to destroy the country."

The statement issued Monday, called "Justice or Violence," followed a week of clashes between police and demonstrators marking the anniversary of the killing a year ago of three Communist leaders. Last Wednesday, a controversial progovernment neighborhood organizer was slain, allegedly by leftist gunmen.

The bishops have criticized Gen. Pinochet for his human rights record before and called for a prompt return to democracy. Last year the conservative archbishop of Santiago, Cardinal Juan Francisco Fresno, sponsored a "National Accord" between opposition political parties from right to left. The accord, which called for elections and the lifting of emergency measures, was abruptly rejected by Pinochet.

But the church has never before referred directly to the government's controversial constitution, perhaps the most important point at issue between the military government and the opposition.

"The Chilean people need to know that in the near future they will be able to organize their civic life according to the wishes of the great majority," the document said.

Under the constitution, which was passed in a controversial referendum in 1980, there is to be a plebiscite in 1989 to approve a single presidential candidate named by military commanders-in-chief for the next eight-year term. If the candidate wins he becomes president, but if he loses there would be a full-scale election. A partly elected congress would then take office in 1990, after elections in which Marxist parties would be banned.

Referring to the courts, which recently released all the police agents accused of involvement in the kidnaping of the three Communists who were found dead a year ago, the bishops said: "It is not enough to say that justice takes time, but will be done . . . . God requires justice and truth without ambiguities."

Interior Minister Ricardo Garcia, a government moderate, said the bishops' concern about violence "appears to be the same as ours." But he made no comment on the references to the constitution.

Recent violence has alarmed both church and opposition leaders, who fear an uncontrolled spiral of clashes with police and revenge killings.

Today, riot police using tear gas and water cannons scattered hundreds of university students protesting the government's educational policies. About 40 students were arrested, police said.

Last Wednesday, Simon Yevenes, a right-wing neighborhood leader, under investigation for firing on protesters last year, was shot to death in southern Santiago, allegedly by uniformed left-wing militia.

Among incidents elsewhere , barricades were built by protesters yesterday in working-class areas in the northern desert town of Calama after a mass in memory of the slain Communists, and about 100 arrests were made. Troops halted 2,000 miners marching in protest from the nearby Chuquicamata copper mine.

Last week, the government turned an existing suspension of political party meetings into an outright ban.