BERKELEY (BCN) — Three workers were taken to the hospital and several others were affected after being exposed to high levels of carbon monoxide at a construction site, according to Berkeley Fire Department officials.

The exposure was due to “construction activities,” according to fire officials.

There are currently no risks to anyone outside the building where the victims were working, fire officials said.

The fire department did not say what building was affected, how badly the three workers were injured, what the source of the carbon monoxide was or what time the incident occurred.