BOSTON -- Ten people were sickened by high levels of carbon monoxide inside a Chelsea apartment building on Saturday, fire officials said.

The victims were treated for symptoms of carbon monoxide poisoning at a local hospital in the afternoon. All are expected to recover.

The building, located at 125 Arlington St., was evacuated after the carbon monoxide was detected. The owner and a crew from the gas company were still inspecting the property in the early evening, but a faulty burner is believed to be responsible for the leak, a Chelsea fire official said.