VANCOUVER, Wash. -

School officials in Clark County are closing an elementary school on Friday after students and staff fell sick with diarrhea and vomiting.

Evergreen Public Schools said Thursday that the county health department had asked the district to close Columbia Valley Elementary School until Monday morning.

District spokeswoman Gail Spolar says about 40 staff and students, or about 7 percent of the school population, either called in sick or left early on Wednesday.

The Columbian reports that the health department was not able to pinpoint the cause of the gastrointestinal illness.

Crews will deep clean the school's surfaces.

Parents were asked to keep children at home until they no longer have symptoms for 48 hours.