AAP

A truck driver who allegedly fled the scene of a bus rollover in Perth in which 16 schoolchildren were injured has been charged with failing to stop and report an accident.

One student remains in a serious but stable condition and two others are in a stable condition at Princess Margaret Hospital after the crash at Wattle Grove in the city's east about 3.50pm (WST) on Thursday.

The driver and 13 other students sustained lesser injuries.

Police said the Transperth bus, with 25 passengers aboard, swerved to avoid a light truck at an intersection then hit a pole and rolled over.

Nine ambulances ferried children and the bus driver to the Princess Margaret and Royal Perth hospitals.

Police sought the truck driver, who allegedly fled the scene after the crash.

A 31-year-old man from Beechboro in the city's east was later detained and charged with failing to stop and failing to report an accident.

The students on the bus were from St Brigid's College and Lesmurdie Senior High School.

One student told the West Australian newspaper the crash was chaotic.

"Everyone was screaming and shouting and then the bus rolled over," the student said. "After a few seconds, I looked up and saw some kids bleeding."