Man arrested after Sydney school bus crash

A knife-wielding man who threatened the driver of a packed school bus involved in a collision in Sydney's southeast has been charged with assault.

About 57 primary school students and three teachers were on board the bus when it collided with a car on Anzac Parade in Kingsford on Friday afternoon.

It's alleged the 22-year-old driver of the car got out and tried to force open the bus door, causing damage.

The 60-year-old bus driver struggled to restrain the man, before he returned to his car and armed himself with a utility knife, police said.

The bus driver re-boarded the bus, locked the door and drove away before calling police.

Officers seized the utility knife and allegedly found a pipe for smoking methylamphetamine in the 22-year-old's car.

The Kingsford man was charged with common assault, and destroy or damage property.

He was granted conditional bail and is due to face Waverley Local Court on September 17.