Puebla, Mexico - As if the deadly earthquake in Mexico weren't enough, a volcano erupted amid the violent tremors.

Popocatepetl - about 45 miles southeast of quake-ravaged Mexico City and some 30 miles from the temblor's epicenter - belched ash and gas as the 7.1-magnitude earthquake rocked the country's central region.

Mexico's volcano-monitoring system registered 1 explosion and 256 "low-intensity exhalations" between Tuesday and Wednesday mornings but the National Center for Prevention of Disasters said none of the activity can be attributed to the earthquake.

A church in Atzitzihuacan at the foot of the mountain collapsed during the quake and eruption, killing 15 worshipers as they celebrated Mass inside.

Pope Francis said he was praying for victims in the majority-Catholic country. "In this moment of pain, I want to express my closeness and prayers to all the beloved Mexican people," he said.

The 17,700-foot Popocatepetl has been particularly active this summer and also blew its top amid the August 21 solar eclipse.