Mexico City, Mexico - US airlines cancelled more flights to Mexico City as volcano ash clouds continue to threaten normal operations. Authorities said that they were forced to ground flights as a precautionary measure as the Popocatepetl volcano continued to emit vapor and ash.

According to reports, Alaska Airlines, AirTran and Delta cancelled more than a dozen flights. Tourists, who were supposed to travel to Mexico, had to cancel their flight tickets.

Claudia Dominguez, spokeswoman for the Mexico City civil defense office, said the very fine ash had been floating around the city owing to the recent volcanic eruption and was brought to earth by recent rainfall. She said no new ash fall had been reported Saturday, despite continuous eruptions of vapor and ash into the air from the 15,000-foot (5,450 meter) volcano.

If you are planning a trip to Mexico, be sure to check with airport authorities to get information on latest flight schedules.