A panel of experts recommended raising the alert level on the volcano, located 70km southeast of Mexico City, after a gradual increase in rumblings and expulsions of hot rock and ash, the country’s head of civil protection, Laura Velazquez, said in a press conference carried live by Milenio TV.

The alert level was raised to “yellow three” from “yellow two”, leaving a “stoplight” one level away from red. Officials were ordered to make checks on evacuation routes and emergency shelters in case of need, Velazquez said.

The state capital of Puebla was covered by ash for the first time in around a decade and its airport was closed on Sunday, Milenio TV reported. Mexico City’s main airport stopped flights for almost six hours Saturday.