Authorities are investigating a morning incident on Merrylands Road as an unprovoked attack, according to reports from 9News.

Emergency responders attended to three victims, with one individual succumbing to their injuries at the scene.

Two other victims, a man and a woman in their twenties, were urgently transported to Westmead Hospital, both in critical condition.

Reports indicate that the man sustained a serious neck stab wound, while the woman suffered life-threatening injuries to her chest and abdomen.

The deceased victim has yet to be officially identified by authorities.

A suspect was apprehended on Smythe Street in Merrylands and is currently being held at Granville Police Station.

Police have since been searching the front yard and driveway of a home.

The scene of the stabbing is in a high-pedestrian area, right by a shopping centre and train station.