Southern Metro Regional Crime Team detectives are appealing for assistance from the public after a pregnant woman was assaulted with a hammer during an armed robbery on Tuesday night in Noble Park. A 24-year-old woman was walking by herself west along Walsh Street towards the intersection of Simpson Street about 11.30pm when a car turned onto the road from Myrtle Street. The vehicle, described by the victim as a silver or blue Ford Falcon XR 6 sedan, drove passed her and one of the occupants whistled at her. Four men wearing masks then left the car and approached the woman. One was armed with a baseball bat, another was carrying a hammer and the other was holding an axe or a similar-shaped weapon. Two of the offenders are described as being 180cm tall, while the other is believed to be about 170cm tall. All three men are perceived to be of African appearance and were wearing black clothing, as well as dark coloured ski masks.