GUARDS shot dead a man during a bungled robbery of an armoured car in Parramatta last night.

Three masked men, one carrying a firearm, threatened three Armaguard security guards after their van had stopped outside an NAB bank on George Street about 6.30pm, police said.

Acting Superintendent David Egan-Lee said two of the guards allegedly shot at the masked men, wounding one, before the three men fled in a white Mitsubishi Lancer with stolen number plates.

A 25-year-old man with a bullet wound was dropped at Auburn Hospital, but was dead when staff found him.

Police could not confirm that he had been involved in the shooting.

The robbers were armed with at least two weapons, one of which was a pistol that was recovered at the scene.

Superintendent Egan-Lee said the two guards had got out of the front of the van but it is not known if the guard at the back left the vehicle. Two shots were fired by the guards and one of the robbers was hit in the chest.

They escaped through a back lane and the Mitsubishi Lancer was seen driving erratically. The robbers were wearing dark hooded jackets and scarves across their faces.

Police established crime scenes in George Street and at Auburn Hospital.

It is believed that none of the guards or either of the surviving masked men was injured.

Police urged anyone with information to contact Parramatta police on 96339633 or Crime Stoppers on 1800333000.