(BusinessWorld) State volcanologists on Friday said Taal Volcano’s next eruption could be stronger after it spewed steam and rocks hundreds of meters into the sky the day earlier, prompting thousands to flee.

Taal continues to emit smoke, which is caused by gas and water vapor moving up toward its crater, said Renato Solidum, chief of the Philippine Institute of Volcanology and Seismology.

“We hope there won’t be stronger eruptions but that’s the threat from Taal because it continues to emit gases,” he told a televised news briefing in Filipino.

Taal has been belching sulphur dioxide for days, creating a thick haze over Metro Manila and surrounding provinces.

The Department of Health (DoH) advised people to take precautionary measures against toxic gas emissions from Taal Volcano’s eruption.

In an advisory issued late Thursday, the agency said short-term exposure to sulfur dioxide, a colorless toxic gas emitted by the volcano, could harm the respiratory system and make breathing difficult.

“People with asthma, particularly children are sensitive to these effects,” DoH said. “Prolonged exposure or high concentrations of this gas can cause inflammation and irritation of the respiratory system.”