Four arrested over Melbourne carjacking

Police have arrested a further three men following a carjacking in Melbourne's west.

A 59-year-old man was in the driver's seat of a BMW sedan at Newport early on Wednesday morning when he was approached by four males, one of whom was armed with a knife, police say.

A 17-year-old from Braybrook fled in the BMW, but was arrested at a Point Cook car park about 45 minutes later, with the car found nearby.

The trio were later arrested at a home at nearby Altona and a silver sedan was seized.