Manila Mayor Francisco “Isko Moreno” Domagoso issued an urgent public warning Tuesday as air quality across the capital deteriorated significantly due to transboundary haze originating from forest and land fires in Kalimantan and Sumatra, Indonesia.

During a live broadcast, Domagoso reported that municipal monitoring stations recorded alarming pollution levels early Tuesday morning.

Three stations — at Puregold Tayuman, Anda Circle and San Sebastian Residences — logged “Very Unhealthy” Air Quality Index levels. Two additional stations at Sta. Ana Hospital and Rajah Sulayman Park recorded levels deemed “Unhealthy for Sensitive Groups.”

Data from the Department of Environment and Natural Resources Environmental Management Bureau confirmed the degradation, with its Mehan Garden monitoring station in Manila recording an AQI of 231, classified as “Acutely Unhealthy.”

Domagoso urged residents, particularly senior citizens, pregnant women, students and individuals with pre-existing medical conditions, to stay indoors, close windows, and wear masks if going outside is necessary.

“It is very important that we use a mask, and if possible, double up because the air we will be breathing in the coming hours is not good,” Domagoso said.

The mayor assured the public that the Manila Health Department and the city’s seven district hospitals are on heightened alert for a potential surge in respiratory cases, which comes as the city also manages a rise in leptospirosis cases following recent monsoon rains.

Meanwhile, the Office of Civil Defense (OCD) advised residents across Metro Manila to minimize prolonged outdoor exposure.

OCD deputy administrator Bernardo Rafaelito Alejandro IV stated that prevailing wind patterns have transported smoke from the Indonesian wildfires into Philippine airspace, prompting continuous monitoring by environmental and disaster response agencies.