SAN PEDRO CHOLULA, Mexico, Dec 25 (Reuters) - Mexico's Popocatepetl volcano continued to blow off steam on Christmas day, keeping authorities on their toes and tens of thousands of evacuees away from home over the holidays.
Mexico's National Disaster Prevention Center (Cenapred) remained on maximum alert as fears continued that the volcano could spring back to life at any moment.
Popocatepetl exploded in a shower of molten rock and sand last Monday in what some experts say was its most violent activity in centuries.
Cenapred officials fear further eruptions could occur at any time as pressure builds again in the volcano's crater behind a dome of lava.
"What is most probable is that this activity will continue as the dome is destroyed," Enrique Guevara, who helps monitor volcanic activity for Cenapred, told Reuters.
"One good sign is that there has been no evidence of new material...there has been no more lava released, which is a good sign because it shows there isn't that much of a pressure build-up in the dome."
About 40,000 residents from around the volcano's base, in the states of Puebla, Morelos and Mexico were evacuated last week to 180 refugee centers.
As Christmas neared and the volcano's activity appeared to subside, many of those residents attempted to return to their homes over recent days.
A military-enforced blockade has made anywhere within an eight-mile (13 km) radius of the colossus off limits.
Popocatepetl, which means "smoking mountain" in the indigenous Nahuatl tongue but is known to most as just "El Popo," is located just 40 miles (64 km) from Mexico City's 18 million residents.
The volcano is the second tallest in North America, reaching 17,884 feet (5,451 metres) above sea-level.