Heavy smoke from a landfill fire in the Mexican city of Matamoros is affecting Cameron County residents, according to a Thursday news release.

Heavy smoke from the landfill fire has been affecting Cameron County residents since Wednesday night, the release stated.

The Office of Cameron County Judge Eddie Treviño, Jr. and the Cameron County Office of Emergency Management department are monitoring the situation, the release stated. “Those who are sensitive to air quality issues or have pre-existing conditions such as asthma, lung disease or related conditions should exercise additional measures of caution,” the release stated.

Residents are urged to remain indoors whenever possible, wear an “approved” mask while outdoors, and keeping doors and windows closed.