A MAN has allegedly gone berserk while waiting to pat koalas at a conservation park, assaulting four people before pulling a knife.

The Para Hills man, 34, was allegedly at an Adelaide Hills wildlife park on Saturday when he assaulted another man at a koala enclosure.

Police would not specify the park in which the incident occurred.

The man - who was waiting to pat the koalas - then allegedly assaulted two other patrons and a staff member who intervened, before threatening one of them with a knife.

He drove off in his car before police arrived to investigate the incident, which happened around 11.30am.

Police arrested him on Monday at the Holden Hill Police Station.

He was charged with charged with aggravated assault and two counts of assault and bailed to appear in the Mount Barker Magistrates Court in early March.