Mexican volcano erupts

The Popocatepetl volcano spews lava, ash and steam during an eruption seen from Santiago Xalitzintla, Mexico, July 7, 2013.

Mexico's National Center for Disaster Prevention reported there had been three explosive eruptions at the peak late Friday and early Saturday - events that usually toss glowing-hot rock on the volcano's flanks.

A rainbow forms over the town of Santiago Xalizintla where the Popocatepetl volcano is covered by clouds, July 8, 2013.

The Environment Ministry has urged residents to take preventive measures to deal with the ash, including wearing dust masks, covering water supplies and staying indoors as needed.

A plume of ash and steam rises from the Popocatepetl volcano, July 7, 2013.

Just east of Mexico City, the volcano has spit out a cloud of ash and vapor 2 miles high over several days of eruptions.

A plume of ash and steam rise from the Popocatepetl volcano, overshadowing the Catholic church in Santiago Xalizintla, Mexico, July 7, 2013.

A plume of ash and steam rises from the Popocatepetl volcano, July 7, 2013.

The Popocatepetl volcano spews lava, ash and steam during an eruption seen from Santiago Xalitzintla, Mexico, July 7, 2013.

A cloud of ash belches out of Mexico's Popocatepetl volcano, some 35 miles from Mexico City, May 20, 2013.

Authorities have raised the alert level to "Yellow Phase Three," the fifth of a seven-stage warning system, restricting access to an area of about seven miles around the volcano while preparing evacuation routes and shelters.

A man walks with a horse and a dog next to signs reading "Evacuation route" in the community of Santiago Xalitzintla, near the Popocatepetl volcano, May 19, 2013.

People observe the Popocatepetl Volcano spewing a cloud of ash and smoke, from Santiago Xalitxintla, in Puebla, May 18, 2013.

A cloud of ash belches out of Mexico's Popocatepetl volcano, some 35 miles from Mexico City, May 15, 2013.

Some of the material fell on three towns while glowing rocks landed on the towering mountain's slope.

Two members of the Federal Police talk with the Popocatepetl volcano in the background in Paso de Cortez, May 19, 2013.

The Popocatepetl Volcano, Mexico's second highest peak just 35 miles southeast of Mexico City, is seen spewing a cloud of ash and smoke, May 14, 2013.

People walk along the streets of the Santiago Xalitzintla community, near the Popocatepetl volcano, May 19, 2013.

The Popocatepetl Volcano is seen from Santiago Xalitxintla, in Puebla, May 14, 2013.

A man sweeps the street in the Santiago Xalitzintla community in Puebla state, near the Popocatepetl Volcano, May 19, 2013.

The Popocatepetl Volcano looms in the background as a man rides his bicycle in San Nicolas de los Ranchos, in the state of Puebla, May 14, 2013.

A farmer plows the land, with the Popocatepetl Volcano in the background, in San Nicolas de los Ranchos, May 14, 2013.

The Popocatepetl Volcano is seen spewing a cloud of ash and smoke from San Nicolas de los Ranchos, in the state of Puebla, May 14, 2013.

A peasant is seen working as the Popocatepetl Volcano, Mexico's second highest peak, is seen in the background, May 18, 2013.

A cloud of ash belches out of Mexico's Popocatepetl volcano, some 35 miles from Mexico City, May 15, 2013.

People are seen at the main square of San Nicolas de los Ranchos, Puebla state, which could be affected if the Popocatepetl Volcano erupts, May 18, 2013.