West Babylon High School reopened Wednesday after chemical fumes forced the evacuation of students and staff on Tuesday, with more than 30 people taken to the hospital for treatment, officials said.

In a statement issued at about 8 p.m. Tuesday, school district superintendent Yiendhy Farrelly said classes would resume at 9:30 a.m. Wednesday. Though law enforcement will continue to investigate, the building was deemed safe for students and staff, she said.

advertisement | advertise on newsday

A 911 call at 11:50 a.m. Tuesday reported “some type of fumes,” Suffolk County police said, but the source of the fumes was unclear. About 34 students and staff were taken to hospitals with difficulty breathing and a burning sensation in the backs of their throats, officials said.

Police and emergency medical personnel were on the scene for several hours and into the evening Tuesday.

A school spokeswoman said school officials were examining security footage for information about the odor’s origin. The school issued a statement saying it was dismissing students early and that an “odor was detected in the hallway, students were evacuated and the fire department was called.”

After-school and evening activities were canceled Tuesday.