Suspicious item declared safe by bomb squad after five-hour operation in Sydney's west

Two men have been arrested as bomb squad police wind down their operation in a western Sydney carpark.

Emergency services have been on-site at Allen Place in Penrith since 11.40am today.

The focus of the operation was a white Mitsubishi Magna, which was thoroughly searched by specialist officers before being declared safe.

Police had earlier arrested two men in the vicinity, one on foot and one in the car.

During the search of the vehicle, a suspicious item was located in the boot.

Police established a 50m exclusion zone around the vehicle as bomb squad officers investigated.

The suspicious item has now been safe, however, police are expected to remain on-site until about 6.30pm (AEDT).

The two men arrested earlier remain in custody and are assisting with inquiries.