Mexico's Popocatepetl volcano, outside the capital, rumbled continuously and spewed gases and glowing rocks to almost one mile (one kilometer) beyond its crater, authorities said Friday.

In an increase of activity the volcano registered "62 expulsions of medium intensity, with the emission of water vapor, gas, ashes and glowing rocks," between Thursday night and Friday, said a statement from the National Center of Disaster Prevention.

Authorities raised the alert level Monday to five on a seven-point scale, extending a security radius around the 5.452-meter (17,887-feet) volcano but stopping short of starting evacuations from nearby communities.

Residents in the nearby town of Santiago Xalitzintla said the volcano was now constantly rumbling.

"There was a strong humming sound all night... it's roaring," said Alvaro Perez.

Another resident said her family was scared of what might happen next.

"My smallest son, who is four years old, was woken up by the roar during the night," said Sofia Lopez. "'Mum, are we leaving now?' he asked me. I told him that it was OK, but the truth is that we're very scared."

Officials in the central state of Puebla have prepared temporary shelters for possible evacuations and locals were wearing face masks to protect their lungs from ashes in a populous area around the volcano.

Popocatepetl, Mexico's second highest peak, means "smoking mountain" in the indigenous Nahuatl language.

After moderate activity during most of the 20th Century, the towering mountain registered more intense rumblings from 1994, with the strongest in December 2000 when nearby communities were evacuated.