UPDATED 05/24/12 1:58 p.m.

CHICAGO (CBS) – Tanning and nail salons in the affluent Lincoln Park neighborhood have seen an increase in unusual robberies in recent days.

Robbers – sometimes armed with knives and syringes, have struck at least five neighborhood businesses since ay 15, Area Central detectives said in a community alert issued Wednesday.

Police said the robbers have been striking nail and tanning salons.

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During the robberies, the suspect passes a note to a clerk warning he or she is armed with a syringe, knife or gun. Suspects displayed a syringe or knife in two of the robberies, the alert said.

The suspects take money from the cash register, then flee.

Both a man and a woman are being sought in connection with the robberies, although only one will enter the business during each robbery, according to the alert.

The robberies all occurred in the western part of the Lincoln Park neighborhood, many of them close to DePaul University.

Two businesses on Fullerton Avenue were robbed – one in the 1300 block around 5:30 p.m. May 15, and another in the 1200 block around 9:15 a.m. Monday.

Two more businesses on Webster Avenue – in the 900 and 1100 blocks were also robbed, around 10:10 a.m. Tuesday and 4:50 p.m. Thursday, respectively.

A business in the 2000 block of North Clybourn Avenue was also hit at 11 a.m. Sunday, the alert said.

It is not clear if there were any other robberies, but police said they all happened between Fullerton and Webster avenues and between Clark Street and Clybourn Avenue.

The male suspect is being sought is described as a white man, 25 to 30 year old, 5-foot-8 to 5-foot-9 and 150 to 180 pounds. He sometimes wears black sunglasses, police said. The female suspect is described as 18 to 25 years old with long blond hair, standing 5-foot-7 weighing 130 pounds.

Anyone with information on any of the robberies is asked to call Area Central detectives at (312) 747-8382.

The Sun-Times Media Wire contributed to this report.

© Sun-Times Media Wire Chicago Sun-Times 2012. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.

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