VATICAN CITY — Remembering the three U.S. religious women and a laywoman brutally murdered during El Salvador's civil war, Pope Francis hailed them as examples of faith and missionary discipleship.

Before concluding his weekly general audience Dec. 2, the pope commemorated the 40th anniversary of the death of the four American missionaries: Maryknoll Sisters Maura Clarke and Ita Ford, Ursuline Sister Dorothy Kazel and lay missionary Jean Donovan.

"With evangelical commitment and taking great risks, they brought food and medicine to displaced people and helped the poorest families," he said. "These women lived their faith with great generosity. They are an example for all to become faithful missionary disciples."

The December 1980 murder of the four missionaries capped a deadly year for the Catholic Church in El Salvador. In March of that same year, St. Oscar Romero, then-archbishop of San Salvador and a critic of the right-wing government's use of violence and torture in the country, was murdered while celebrating Mass.

Donovan and Sisters Clarke, Ford and Kazel were returning from El Salvador International Airport when their vehicle was stopped by military guardsmen. They were subsequently abducted, raped and shot to death.

Their deaths drew outrage in the United States, prompting the government, which at the time was allied to the Salvadoran right-wing regime, to call for an investigation.

According to a 1998 report by the New York Times, the four guardsmen, who were convicted in 1984 for the brutal killing, admitted that they were ordered by Salvadoran government authorities to carry out the murders.

Commemorations of the four women's deaths were being held in El Salvador, in the United States and in Rome.