Three youths were apprehended after allegedly assaulting a delivery driver at Morphett Vale last night.

Police and paramedics responded to reports of a disturbance at a petrol station on Main South Road, Morphett Vale just before 11pm on Monday 27 December.

A driver was making deliveries to the service station and a group of youths got into the rear of his truck.  When the driver confronted them, they allegedly turned on him and assaulted him.

The youths ran off into a nearby creek line.  Fortunately, PolAir was almost immediately overhead and tracked the youths to a large open drain near Jordan Drive where they became trapped and couldn't get out.

MFS crews were called to assist with ladders and other equipment.

A 13-year-old Christies Beach boy and a 14-year-old Morphett Vale boy were arrested and charged with assault.  They were both bailed to appear in the Christies Beach Youth Court on 17 February.

A third youth, aged 14, slipped and fell when entering the drain and sustained a laceration to the head.  He was conveyed to the Flinders Medical Centre for treatment and will be spoken to by police after his release.