CHICAGO (CBS) — Police are asking for the public’s help in finding a man suspected of robbing three fast food restaurants in three days this month in Hammond, Indiana.

Most recently, the man showed a handgun and demanded money about 8:50 p.m. Dec. 12 at a Subway in the 1400 block of Indianapolis Boulevard, according to Hammond police. He made off with an undisclosed amount of cash.

Surveillance image of a man suspected of robbing three fast food restaurants in Hammond, Indiana. (Credit: Hammond Police)

About three hours earlier just blocks away, the same suspect is thought to have produced a note demanding money and threatening the cashier at a Burger King in the 1800 block of Indianapolis Boulevard, police said. In that incident, he left before he could get any proceeds.

About 2:05 p.m. Dec. 9, he lifted his shirt to display a firearm and handed a note to a cashier demanding cash at a KFC in the 2700 block of 169th Street, police said. He received an undisclosed amount of money and took off westbound from the restaurant.

The suspect is described as a 140-pound white man, thought to be between 20 and 30 years old, standing between 5-foot-8 and 6 feet, police said. In the Burger King and KFC incidents, he was wearing a black Northwestern hooded sweatshirt, a black mask and sunglasses.

Anyone with information about the robberies is asked to contact Detective Sgt. Stephen Guernsey at (219) 852-2978.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2017. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)