This is an archived article that was published on sltrib.com in 2013, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Mexico City • Airport officials say at least six U.S. airlines have canceled more than 40 flights into and out of Mexico City and Toluca airports after the Popocatepetl volcano spewed out ash, steam and glowing rocks.

Mexico City airport spokesman Jorge Gomez says U.S. Airways, Delta, United, American and Alaska Airlines canceled 47 flights as a precaution. But he says the airport otherwise continues to operate normally and that no ash has reached the area.

At nearby Toluca airport, Spirit Airlines canceled flights from Dallas and Fort Lauderdale.

Toluca airport spokesman Alejandro Munoz says the airport also continues to operate normally.

Authorities registered several tremors Tuesday at the 17,886-foot (5,450-meter) volcano, which has been spraying a fountain of hot rock and ash for the last 24 hours.