Police say a shooting outside a Melbourne nightclub in Australia has left at least two people critically wounded.

Police are investigating and appealing for anyone with video footage or information to come forward.

They believe several people were shot outside the two-story Love Machine club early Sunday but have made no arrests so far.

Four people have been taken to a hospital but two are said to be critical.

The Seven Network TV station says a security guard at the club had no idea a shooting had happened and there was no panic inside the venue, which was still open.