A New Jersey high school has been evacuated and about two dozen students taken to a hospital after what police are calling a chemistry lab "mishap" involving acid.

Police in Woolwich say none of the Kingsway Regional High School students are believed to have life-threatening injuries after the incident a little after 8 a.m. Heavy smoke was reported in the school.

Authorities say a school bus is taking 20 to 25 students to Crozer-Chester Medical Centers in Upland, Pennsylvania.

Police say the entire school was evacuated. It's not clear when the school was being reopened.

It's not clear what caused the lab accident.