Workers on Sunday walk along a street that was damaged by heavy rain in San Martin, on the outskirts of the Salvadoran capital, San Salvador. (Luis Romero/Associated Press)

Civil defence officials in El Salvador said Sunday night that the death toll from rain-triggered floods and mudslides has risen to 124, with another 60 people missing.

The government's previous toll had been 91 dead and 60 missing, with 7,000 homes damaged.

Salvadoran Interior Minister Humberto Centeno said there have been deaths in at least five of the 14 provinces of the tiny, mountainous Central American country.

Centeno, who heads the Civil Protection agency, said the rising toll and President Mauricio Funes' declaration of a national emergency "changes the panorama" and means state officials will take a greater role in rescue and recovery efforts.

Mud and boulders loosened by heavy rains swept down a volcano and partly buried the town of Verapaz on Sunday, swallowing homes.

The capital of San Salvador and central San Vicente province are the hardest-hit regions.

Fallen trees and other debris litter the roads, making it difficult for aid workers to get to the city of San Vincente.

"In the streets, you see people drenched in water and muddy," said Laura Mata of World Vision. "All we have is mud up to our legs and trees have fallen down. We are really worried.

"It's very hard because people are already poor."

Government officials said about 7,000 people have gone to shelters.

The rains were caused by a low-pressure system off the country's Pacific coast, meteorologists said.

Dave Roberts of the U.S. National Hurricane Center in Miami said while the presence of Hurricane Ida in the Caribbean may have played some indirect role in helping steer the system, the deaths are not directly linked to the hurricane.

Ida made landfall Thursday over east-central Nicaragua, destroying hundreds of homes and power lines, before weakening to a tropical storm.

Ida then regained strength to become a Category 2 hurricane Sunday afternoon, with sustained winds of 160 kilometres an hour and stronger gusts as it passed near the tip of Mexico's Yucatan Peninsula.

With files from The Associated Press