The country’s National Disaster Prevention Center said that the explosion resulted from a fracture bursting through the lava dome at Popocatepetl’s summit.
The ash plume was clearly visible from the heart of the capital, which is home to about 20 million people.
But officials said the ash did not pose a significant threat to anyone living in the region.
The volcano has been erupting intermittently since December 1994.
An eruption in December 2000 spewed lava and prompted the evacuation of about 30,000 people.
The towering mountain has become increasingly active in recent weeks.
Photo: Julio Cesar Gervacio - Flilckr