Two UberEats deliverymen riding a scooter have been killed after they were hit by a bus and car while waiting at an intersection.

The 32-year-old rider and his passenger, 44, were waiting to turn onto Vivienne Street in Kingsgrove, southern Sydney, about 8.20pm on Monday.

The bus driver, 49, was allegedly using his mobile phone when the crash happened.

One of the Uber Eats deliverymen was thrown from the scooter after being hit from behind by the bus. He was flung into the path of a car and killed instantly.

Two men riding a scooter (pictured) have been killed after they were ploughed into by both a bus and a car while waiting at an intersection

New South Wales Police are still investigating the circumstances of the crash as they are unsure exactly what happened (aftermath of the crash, pictured)

One of the Uber Eats deliverymen was thrown from the scooter after being hit from behind by the bus (stock image)

Witness Kyle Johnston said he saw one of the men become trapped in the car's wheels.

'I witnessed a car drag a body, about 15m today, and I'm kind of confused as to what happened,' he told Nine News.

A Traffic and Highway Patrol Command spokeswoman said the crash involved a Honda CRV 4WD.

NSW Police Assistant Commissioner Michael Corboy said the scooter crash was 'tragic'.

'I can confirm that two persons from Hurstville were killed in that crash, it appears that while stationary, the two people on the scooter - a rider and a pillion - were struck from behind and unfortunately the rider was thrown in the path of another vehicle and was killed instantly,' he said.

'The passenger died a short time later. As a result of that, we have interviewed the bus driver, there has been some CCTV from on that bus, and we will be alleging that that bus driver was on his mobile phone as well as not wearing his seat belt at the time.

'Really concerning stuff for us as police that that occurred and two people lost their lives tragically where they didn't have to.

'That driver has been interviewed and he's currently in custody waiting for court, he's been charged with dangerous driving causing death using a mobile phone and some other serious offences.'

The bus driver has been charged with two counts of dangerous driving occasioning death, two counts of negligent driving occasioning death, driver using mobile phone when not permitted and driver not wear seatbelt.

The 32-year-old rider and his passenger, aged in his 30s, were waiting to turn onto Vivienne Street in Kingsgrove, southern Sydney (pictured) about 8.20pm on Monday

He was refused bail and will appear in Sutherland Local Court on Tuesday.

Emergency responders were at the scene on Monday night, and had cordoned off part of the intersection.

The mangled scooter and a helmet were seen strewn on the road, while part of the bus's windscreen was smashed.