Sobbing Mexican families followed coffins through the streets and picked nervously at the ruins of their homes Sunday as help trickled in after a huge earthquake killed 90 people.

"I don't know if I am crying from sadness, from shock, or from fear of what might happen next, and how we will live," said Refugio Portales, in the hard-hit town of Juchitan.

She followed the white coffin of a friend on the back of a truck to the shrill sound of pipes.

Mexican seismological authorities measured Thursday night's quake at magnitude 8.2, under the Pacific off the coast of Chiapas state.

That was bigger even than the 8.1 quake that killed 10,000 people in Mexico City in 1985.

- Fearing aftershocks -

People in Juchitan were afraid to return to their homes, fearing the effects of hundreds of aftershocks -- but camped within sight of them to prevent looting.

Juana Luis, 40, spent the night with her family under a tree in the garden next to their house, which was reduced to a pile of concrete rubble, twisted metal and electrical cables.

"It is very sad to live like this, on hammocks hung in the garden, under the rain, with our belongings buried in the house," she told AFP.

Luis secured some emergency food handouts, but food prices have soared in the disaster zone.

"We used to get a chicken for 70 pesos and now it costs 300. That makes me really anxious, because however much I want to buy something for my children when they ask me, I can't afford to," she said in tears.

- 'No one has come' -

As soldiers and mechanical diggers worked to clear the ruins of the town hall, some picked cautiously through the rubble to salvage household items.

"We are afraid to go inside our houses to remove the rubble, but we have no other choice because no one is coming to help us," said Carlos Villalobos Martinez, a retired man of 58.

He said he escaped "by a miracle" with his wife and three children when their house collapsed.

On the square near the town's Martes Santo church, a group of women camped in the rain, cooked eggs on a fire and prepared corn tortillas.

"We still have no water or electricity. We are sleeping with the children out here in the open," said one of them, Maria de los Angeles Orozco.

"No one has come to help us."

Ivan Rodriguez, 40, echoed that sentiment, telling AFP "we've received very little help."

"We've lost everything, truly: work -- we can't work -- we don't know what to do," the craftsman said.

Authorities counted all the fatalities in the states of Chiapas, Oaxaca and Tabasco.

On Sunday night, the federal government said it confirmed a report that 25 more people had been found dead in Oaxaca, bringing the overall toll to 90.

- 'Titanic task' -

Sobbing relatives marched behind their loved ones' coffins as the first funerals were held for those killed in Juchitan, largely inhabited by indigenous Zapotec people.

Like Portales, local doctor Cristian Juarez, 46, was mourning his grandmother Manuela Villalobos, 85, who died when her house collapsed as she slept.

"She was a very strong woman. She made sure the younger generations were aware of Zapotec traditions, like the funeral rites," he told AFP.

Rescuers arrived in Juchitan from around the country to help clear up, hand out food and aid the sick.

Dressed in orange overalls and a helmet with a torch, Miguel Angel Nava, a member of a volunteer rescue group, joined in a human chain passing belongings out of a ruined house.

"It is no longer a case of searching for people. It is about supporting the community," he said, wiping the sweat from his face.

"It is a titanic task -- it was a quake as bad as the 1985 one. But by joining forces we can do it."