CHATTANOOGA (WRCB) -- Chattanooga Police investigate a string of weekend robberies.

 The Walgreen's at 2289 Gunbarrel Road was robbed at 4am Monday. Police say two suspects entered the store armed with handguns.

They told a clerk and a manager to walk to the back office. The store manager was told to open the store safe and one of the suspects hit him in  the head as he tried to do so.

 After the suspects obtained the money, they fled the store with more than $3500. The pair was described as black males wearing bandanas over their faces and hooded sweatshirts. The store manager was treated on-scene for the blow to the head.

 Another robbery happened at 11:30pm Sunday at 600 Ashland Terrace. The store clerk told police that black male entered the store and demanded money. He got $50 then he fled from the store. No one was hurt.

 Finally we have a robbery at the Books-A-Million at 2020 Gunbarrel Road. Police say the suspect was able to get away with more than $600. A black male reportedly asked a clerk around 3:30pm Sunday about the cost of a book.

When she responded, he told her he'd take the book and the money from the register. After getting the money, the suspect made the clerk walk to the back of the store. He then fled to the back of the store.

 This is the second time in two weeks that the store has been robbed. The suspect in both robberies was described as a black male with twisted hair, between 5'08 and 5'10, weighing about 200 lbs.

 Investigators are still working on suspect leads in all of the investigations. If anyone has information about any of these incidents, they are asked to call the Chattanooga Police Department Property Crimes Division at 423-698-2525.