Police are appealing for information after a man was last seen being dragged screaming into a car in Sydney's south-west on the weekend.

About 5am on Sunday, witnesses said they saw a man being forced to get into a dark-coloured hatchback by two other men on Lakemba Street in Wiley Park.

The witnesses told police the man was struggling to get free and screaming for help.

They immediately called police, but when officers arrived the man and the car were gone.