MEXICO CITY (Reuters) - Mexico has lowered the alert level for the Popocatepetl volcano a notch, just weeks after an increased level of explosive activity belched ash over Mexico City and prompted international airlines to suspend flights.

The alert level for the volcano, located some 50 miles to the southeast of the capital, was lowered to yellow phase two from yellow phase three, Mexico City's mayor and Mexico's interior minister said on Twitter without giving details.

The new alert level is the fourth highest and indicates the volcano, nicknamed Don Goyo, could produce sporadic explosions, according to the website of Mexico's National Center for Disaster Prevention.

Four U.S. airlines earlier this month suspended flights to and from Mexico City because of concerns about ash from Popocatepetl.

Mexico raised the alert level on July 6.

(Reporting by Elinor Comlay)