PORT-AU-PRINCE, Haiti — Atop the rubble of destroyed churches, in parks and on sidewalks, thousands of Haitians prayed today in a national day of mourning, one month after a magnitude-7 earthquake killed more than 200,000 and left this Caribbean country struggling for survival.

Leaders of Haiti's two official religions — a Catholic bishop and the head of the Voodoo priests — joined Protestant ministers for a prayer service in the shade of mimosa trees near the shattered National Palace. A Muslim preacher also attended.

Men wore black armbands of mourning, girls frilly white dresses. Among them were earthquake amputees in wheelchairs, casts and hobbling on crutches.

President Rene Preval wept during the service, his black-clad wife trying to console him.

"The pain is too heavy — words cannot describe it," Preval said in one of the first major public addresses he has made in weeks.

Parishioners filled churches in Port-au-Prince's Petionville suburb and set up loudspeakers so those in the streets could follow. Others stood on debris that used to be a Catholic Church and an evangelical church to remember victims anonymously buried in mass graves outside the devastated capital, Port-au-Prince.