A school bus caught fire on a Los Angeles freeway but all 23 students escaped without injury.

City fire spokeswoman Margaret Stewart says the driver noticed smoke while on US 101 near Woodland Hills.

She says the driver pulled to the freeway shoulder, where four adults helped nearly two dozen kids exit. No injuries are reported.

Television news footage showed the bus being engulfed in flames. Westbound lanes were closed while crews doused the fire.

Officials say the bus serves a private school