Mexico's Popocatepetl volcano has seen a dramatic overnight explosion that sent ash blowing over the major city of Puebla directly to the east, forcing closure of the city's airport.

Officials there are urging to people to wear masks to avoid inhaling the fine grit that has covered houses and cars.

Mexico's national disaster prevention agency reports that the eruption began around 2:30 a.m. (3:30 EDT; 0730 GMT) Monday, hurling glowing rock as far as a mile (1.5 kilometer from the crater. Ash rose nearly two miles (3 kilometers) above the crater.

About 25 million people live within 62 miles (100 kilometers) from the crater of the 17,797-foot (5,426-meter) stratovolcano. It's been periodically erupting since 1994.