FRISCO, Texas (CBSDFW.COM) – Three people at Frisco High School have tested positive for COVID-19.

Frisco ISD leaders said Thursday the district learned of all three cases in the last 24 hours.

The school district said it immediately began contact tracing and notified everyone who came into close contact with those who tested positive.

A staff member also tested positive this week at Wakeland High School in Frisco.

The school district said a small number of students and staff are in quarantine.

Frisco ISD went back to school last week.