UPDATE: Traffic heavy after 'horror' Sydney smash that killed two

Peak hour traffic is expected to be heavy in Sydney's inner west after a "horrific" eight-vehicle smash which killed two men and injured four people, including two children.

Seven cars and a truck were involved in the accident on Mary Street near the intersection of Concord Road in Rhodes, with police investigating alcohol and speed as factors of the crash.

Two men, who were travelling in separate cars, were killed in the collision, which happened just before 11am (AEDT).

Two four-year-old girls in separate cars were taken to hospital with minor injuries, while another person had to be cut free from wreckage.

Police described the scene, which was spread over a few hundred metres, as "quite horrific".

At 4.15pm, the Transport Management Centre said Concord Road had been reopened at Rhodes, and all diversions near the smash had been lifted.

It said traffic remained heavy in the area, with motorists advised to allow additional travel time on Monday afternoon.