Over the last two months, authorities say seven victims have had necklaces ripped from their necks near Avalon Boulevard and Anaheim Street.
Some of the robberies have also been in Harbor City.
The robbers have used weapons in some cases.
Police advise residents not to wear exposed jewelry and to be extra aware of their surroundings.
If you have any information regarding these crimes, you are urged to call the LAPD Harbor Station at (310) 726-7900.