Mexico raised its alert level on the Popocatepetl volcano following increased activity and officials were ordered to make checks on evacuation routes and shelters in case of emergency, the head of the country’s civil protection authority said Sunday.

A panel of experts recommended raising the alert “stoplight” to “yellow three” from “yellow two” following a gradual increase in activity, civil protection national coordinator Laura Velazquez said in a press conference carried live by Milenio TV.