Church leaders in the Philippines have called for the resumption of peace talks between the government and communist rebels to end almost half a century of armed insurgency in the country.

The call was made at the end of a three-day "ecumenical church leaders summit on peace" organized by a network of Catholic and Protestant peace advocates and was attended by some 130 priests and lay people last week.

"The church leaders expressed sadness at the recent developments in the negotiations ... that are now suspended indefinitely," read a statement titled "Peace is Possible." 

Archbishop Antonio Ledesma of Cagayan de Oro signed the statement on behalf of the Catholic bishops and Rev. Rex Reyes Jr. of the National Council of Churches in the Philippines.

The summit participants expressed "grave concern" over President Rodrigo Duterte's declaration of "all-out war" and recent attacks by the rebel New People's Army against government troops after talks failed in May.

"Violence is intensifying and spilling over into communities throughout the Philippines. Stories from the regions validated this fact," read the church leaders' statement, adding that in the crossfire, "innocent civilians are victims, especially from indigenous peoples' communities."

The religious leaders said they were "troubled" that the gains of the previous negotiations "would go to waste with the present atmosphere."

The group also appealed for the government to release political prisoners, including a Protestant bishop in Mindanao, and for the rebels to free their "prisoners of war."

"Our hope for a just and enduring peace remains," read the group's statement, adding that they will "help transform this crisis into an opportunity for us to work together."

The peace summit was attended by representatives of the Catholic Bishops' Conference of the Philippines, the Ecumenical Bishops' Forum, the National Council of Churches in the Philippines, the Philippine Council of Evangelical Churches, and the Association of Major Religious Superiors in the Philippines.