The world's most dangerous volcano erupted yesterday, spewing super-heated rock fragments half a mile into the air.
Officials were last night warning that bigger outbursts were likely as the 5,450-metre volcano, southeast of Mexico City, emitted a low-pitched roaring sound not heard in a decade.
Frightened locals fled their homes as a white cloud of ash, gas, water vapour and super-heated rock spewed from the cone of Popocatepetl high above the village of Xalitzintla.
"Up on the mountain, it feels incredible," said local farmer Aaron Sanchez Ocelotl (45). "It sounds like the roaring of the sea."
The white cone of Popo, as most call the mountain, is an iconic backdrop to Mexico City's skyline, but its 40-mile distance means even a large eruption is unlikely to do more than dump ash on one of the world's largest metropolitan areas.
It's a different matter for the villages on the flanks of the volcano. "Everyone needs to take this seriously. This buzzing, this roaring isn't normal," said Gregorio Fuentes Casquera, the assistant mayor of Xalitzintla, a village of 2,600 people about seven miles from the summit.
He said the town had prepared 50 buses and was sending out its six-member police forces to alert people to be ready to evacuate.
More than 30 million people live within view of the volcano. It has been erupting intermittently since December 1994, with its most violent eruption in 1,200 years occurring on December 18, 2000.