Students at a Bronx elementary school were ushered to safety Tuesday as a precaution over carbon monoxide fears.

Administrators at P.S. 170 say the lights started flickering around 1 p.m., prompting them to call the fire department to check carbon monoxide levels at 1598 Townsend Ave. The school says protocol requires they have the levels checked whenever lights flicker. While firefighters found elevated levels in the basement, the levels were normal in parts of the building where children attend school.

Fire officials believe wires may be to blame. Con Edison representatives say the utility company is investigating the cause.

Students were sent to the cafeteria during the incident and their parents were called to pick them up early.