A strong new earthquake shook Mexico on Saturday, causing new alarm in the country. At the site of an office building that collapsed in Mexico City Tuesday, rescuers briefly evacuated before returning to continue their work. (Sept. 23)

Volunteers in Mexico City have organized over social media to direct relief efforts to where they’re most needed after the most deadly series of earthquakes in three decades.

Two deaths resulting from a strong aftershock Sunday brought the death toll to 318 since a magnitude-8.1 quake that battered the Oaxaca region Sept. 7. Sunday’s tremor sowed fear across the country, and a column of ash rose above the Popocatepetl volcano near Mexico City. 

Another strong earthquake registering magnitude 7.1 leveled buildings across the Mexican capital Tuesday.

Gisela Pérez de Acha, a human rights lawyer and journalist, described the volunteer effort from the Centro Horizontal, a cultural center where she works, and where she has been helping to coordinate relief efforts with 50 other volunteers since Tuesday.

More: Magnitude 6.1 earthquake rattles southern Mexico

Previously: Mexico City quake rescuers frantically search for those still alive under school rubble

“We’re covering a governmental void and we’re getting resources where they are needed,” Pérez de Acha told USA TODAY by telephone.

The Mexican government has asked to integrate her group’s real-time maps with their own and is now using them to direct their own efforts, she said.

The latest tremor, registering 6.1, struck on Sunday off the west coast, with its epicenter 62 miles south-southwest of Tonala, in Chiapas, according to Reuters.

The government of Oaxaca state reported that several homes collapsed. A woman was crushed to death when a wall in her home buckled in the town of Asuncion Ixtaltepec, and a man died after a wall fell on him in San Blas Atempa, the Associated Press reported.

Many more quakes are likely, warned Xyoli Perez Campos, director of Mexico’s National Seismological Service, who said more than 4,300 aftershocks have already been counted.

At least 30 people are still believed to be buried in rubble, Mexico City Mayor Angel Mancera said.

“Homes that were…