UPDATED 12:56PM Rescuers pulled survivors and bodies yesterday from the charred aftermath of the powerful eruption of Guatemala's Volcano of Fire, as the death toll rose to 65 and was expected to go higher from a disaster that caught residents of remote mountain hamlets off guard, with little or no time to flee to safety.

Using shovels and backhoes, emergency workers dug through the debris and mud, perilous labor on smoldering terrain still hot enough to melt shoe soles a day after the volcano exploded in a hail of ash, smoke and molten rock.

Bodies were so thickly coated with ash that they looked like statues, and rescuers were forced to use sledgehammers to break through the roofs of houses buried in debris up to their rooflines to try to see if anyone was trapped inside. 

Fanuel Garcia, director of the National Institute of Forensic Sciences, said 62 bodies had been recovered and 13 of those had been identified.

"It is very difficult for us to identify them because some of the dead lost their features or their fingerprints" from the red-hot flows, Garcia said. "We are going to have to resort to other methods ... and if possible take DNA samples to identify them."

Hilda Lopez said her mother and sister were still missing after the slurry of hot gas, ash and rock roared into her village of San Miguel Los Lotes, just below the mountain's flanks. 

"We were at a party, celebrating the birth of a baby, when one of the neighbours shouted at us to come out and see the lava that was coming," the distraught woman said. "We didn't believe it, and when we went out the hot mud was already coming down the street."

"My mother was stuck there, she couldn't get out," said Lopez, weeping and holding her face in her hands.

Her husband, Joel Gonzalez, said his father had also been unable to escape and was believed to be "buried back there, at the house."

Guatemalan authorities say they had been closely monitoring the Volcano of Fire, one of Central America's most active, after activity picked up around 6am on Sunday.

The volcano has registered a number of minor eruptions over the years, and no evacuations were ordered as scientific experts reported the activity was decreasing.

Guatemala's disaster agency, Conred, issued a number of standard precautions, advising people to wear protective face masks, clean their rooftops of ash once the eruption was over and cover any food and water intended for human consumption. It also said to heed any recommendations from authorities. Guatemala City's international airport was closed due to the danger to planes.

Conred spokesman David de Leon said that around 2pm the volcano registered a new, more powerful explosion.

Soon, searing flows of lava, ash and rock mixed with water and debris were gushing down the volcano's flanks, blocking roads and burning homes.

"It traveled much faster. It arrived in communities right when the evacuation alerts were being sent out," de Leon said.

Authorities scrambled to issue an evacuation order. Some communities emptied out safely. But in places like Los Lotes and the village of El Rodeo, about 12 kilometres downslope from the crater, it was too late for many.

The fast-moving flows overtook people in homes and streets with temperatures reaching as high as 700 Celsius, and hot ash and volcanic gases that can cause rapid asphyxiation.

Rafael Letran, a resident of El Rodeo, criticised Conred for not evacuating communities earlier.