Two Kamiloiki Elementary School students were sent to a hospital Tuesday morning after their Hawaii Kai school was evacuated following reports of a strange odor on campus.

The school’s 435 students were escorted at about 11 a.m. to Kaiser High School, where students were released to their parents.

"The staff smelled something in the morning, and it didn’t go away for about an hour, at which point the principal called (the Honolulu Fire Department)," said Donalyn Dela Cruz, spokeswoman for the Department of Education.

Sixteen students and two adults were evaluated at the school, according to city Emergency Medical Services spokeswoman Shayne Enright.

She said an ambulance took two 10-year-old girls in stable condition to a children’s hospital. The girls complained of nausea and dry cough.

Honolulu fire spokesman Capt. Terry Seelig said the department was not able to find the source of the odor or determine what it was.

"It was described as a kind of a chemical odor," Seelig said. "We could smell it ourselves very faintly in some of the perimeter areas but couldn’t detect anything with our meters."

Fire officials also checked the neighboring community and farms in the area but could not identify a source.

On Monday, odors from too much of the pesticide malathion on a home lawn prompted school officials to keep students in their classrooms at two elementary schools in Ewa Beach for more than an hour, and sent a girl to the hospital.

Seven students and two teachers at Pohakea Elementary School complained of watery eyes and eye irritation, and an 11-year-old student at Kaimiloa Elementary was taken in stable condition to a hospital.