MEXICO CITY (CNN) - A thick plume of ash and smoke belched skyward Monday, as Mexico's giant Popocatepetl volcano rumbled for a fifth day.

Nearby residents waited again for a signal that they would be evacuated, but disaster officials said there were no immediate plans for evacuation.

Some 70,000 people who live on the mountain's flanks are on alert. The 17,992-foot (5,452-metre) volcano located near Mexico City sent smoke several miles (kilometers) into the air and spread a blanket of lava and fiery rocks around the peak.

"There are not yet any orders for evacuation ... the volcano is returning to normal," a spokesman at the National Disaster Prevention Committee told Reuters.

He said ash could fall on nearby villages and southern Mexico City.

The exhalation of Popocatepetl, whose name means "smoking mountain" in the native Nahuatl Indian language, followed days of increasing activity and was one of the biggest in recent months.

Some 18 million residents in greater Mexico City live just 40 miles (65 km) away from the volcano popularly referred to as "Popo," but officials say the city is too far away to be in direct danger.

Reuters contributed to this report.