Wildfires in Indonesia have filled the skies with toxic smog for months, and the haze has spread across Southeast Asia, NBC News reported. Heat and drought made worse by a strong El Niño weather pattern have made this the country's worst fire season in more than a decade, the outlet said.

"It looks like Mars, like we're living on another planet," said Natanael Undas, a schoolteacher in Central Kalimantan province, NBC News reported. His family keeps the windows shut. But the smoke still gets into the house and makes his 2-year-old daughter sneeze, the outlet said.

The haze has affected millions of people since the fires started in July and has closed schools in several countries, NBC News reported. Forests and peatlands burn each year as farms clear land, but peat fires are very hard to put out, the outlet said.

On Wednesday, hundreds of students and activists protested in Jakarta and other cities, NBC News reported. They marched against the policies of President Prabowo Subianto. One of their complaints is that he has resisted declaring the fires a national disaster, the outlet said.

In Singapore, air pollution this month hit its highest level since 2015, NBC News reported. On Tuesday, the foreign ministers of Singapore and Indonesia said they were considering a joint task force to fight illegal land burning. "We will use the full force of the law to make sure those who profit from fire must answer for the fires," Indonesian Foreign Minister Arrmanatha Nasir said, according to NBC News.

An Indonesian environmental group named dozens of companies with links to Singapore and Malaysia that it tied to fire hot spots, NBC News reported. On Thursday, Indonesia said police had identified 20 companies suspected of being involved. Malaysia has denied that its companies are involved, the outlet said.

Only NBC News has reported this so far, and NewsHabit hasn't seen independent confirmation.

What we know: The fires are the worst in years, and the smoke is affecting several countries.
What we don't: When the fires will be put out, or whether any companies will be charged.