STORY: Mexico City's Benito Juarez International Airport halted operations for more than five hours on Saturday. Several flights were delayed, and others canceled. The airport resumed operations on Saturday.
Popocatepetl, one of the country's most active volcanoes, has recently intensified its fiery activity.
Earlier this week, several towns closed schools due to volcanic ash.
Popocatepetl, meaning "Smoking Hill" in the native Aztec language Nahuatl, is one of the world's most closely monitored volcanoes. It rises only about 45 miles (72 km) southwest of Mexico City, home to about 9 million people or around 22 million including the metropolitan area.