Police say five separate incidents have been reported since Saturday within a four block radius of South Delaware and Cypress Streets.
Investigators say the attacks took place between 7:00 p.m. and 10:00 p.m. They say, in each case, a Hispanic man had been walking or biking and was attacked by a group of African-American men wearing hoodies.
No one has been seriously injured, but property and cash were stolen. There are no suspect descriptions and police increased patrols and plain clothes officers in the area.