7 high school students have high CO levels in Pa.

UNIONTOWN, Pa. (AP) — Seven students who became sick at a southwestern Pennsylvania high school have tested positive for elevated levels of carbon monoxide.

Uniontown Area School District Superintendent Charles Machesky says two students were tested Friday after complaining they felt ill after returning home from school. He says five more high school students have since tested positive after falling ill.

Machesky says several air quality tests have been performed at the school but no abnormal readings were detected. Another round of tests is set for today.

The school remains open.