Emergency officials say 16 people in North Carolina have been treated for carbon monoxide poisoning after spending time in the same house.

Local media reported four people went to the emergency department at Novant Health Rowan Medical Center in Salisbury late Tuesday afternoon, complaining of dizziness and other symptoms.

The Salisbury Fire Department went to the home and found high levels of carbon monoxide. Firefighters said they also found a portable generator running inside the home, which had no electricity. They shut down the generator and aired out the house.

Tuesday evening 11 more people went to the hospital with the same symptoms. All had been at the home at some point. The homeowner was treated at the house.

Seven people were taken to Duke Medical Center for treatment.