Once again, government authorities in Mexico were forced to raise the alert level for the Popocatepetl volcano, which lies just southeast of Mexico City, due to its increasing activity and the impending possibility of an eruption. The alert level is at the fifth level out of a seven-level scale.

The National Disaster Prevention Center of Mexico said a lava dome appears to be growing in the volcano's crater, meaning it could erupt, worrying officials, reported the Associated Press. Scientists recorded the continued activity of the volcano on Tuesday, which threatens Mexico City's 19 million residents.

Taking precautions, the government has closed off areas close to the volcano, warning people to stay at least seven miles, or 12 kilometers from the crater, reported the AP. As ash continues to spew out from the volcano, authorities are also urging residents in surrounding towns to clean ash from their rooftops and avoid inhaling it.

After witnessing a plume of steam and ash coming from the Popocatepetl volcano, school officials in five towns closed schools and cancelled classes as they prepared for a potential evacuation, reported Reuters.

It sounded like a loud cauldron releasing steam, said Reuters cameraman Roberto Ramirez.

Carlos Gutierrez, head of operations at the National Center for Disaster Prevention, said the activity current alert level could remain for several weeks or months, until the activity of the volcano decreases, reported Reuters.  

For the elderly, this is normal, said Jaime Romero, a construction worker in San Pedro Benito Juarez, a small town near the volcano.  Whatever the volcano wants to do is fine. But younger people, like myself, are always alert,

Emergency workers have been patrolling the area, preparing for potential evacuations if authorities raise the warning stage to a red alert level.

Since Friday, scientists have seen the activity of the volcano increase dramatically.Mexico's National Center for the Prevention of Disasters said they recorded eight vapor releases. The most serious occurred around 9 a.m. Sunday, sending vapor cloud a mile into the air, reported the Houston Chronicle.  

On Monday night, the center said that surrounding areas could experience significant explosions of growing intensity that hurl incandescent rocks significant distances, reported the Associated Press.

Popocatepetl is one of the highest peaks in Mexico, reported CNN. The last eruption occurred on Dec. 18, 2000, when a serious explosion sent hot rock and magma from the crater, forcing thousands to evacuate.