ELMHURST, Ill. (STMW) — A man in a mask robbed a west suburban bank Wednesday morning but was thwarted when a dye pack exploded as he ran away.

The suspect entered the Inland Bank branch at 539 Spring Rd. in Elmhurst a few minutes before 9 a.m., set an object on the ground he claimed was an explosive device, and demanded money, Elmhurst Police Chief Michael Ruth said.

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The suspect took an undetermined amount of cash and ran out the door, Ruth said. Investigators later determined the object on the floor was not an explosive.

Witnesses saw the robber get into the passenger seat of a white or silver SUV at Saylor and Montrose avenues, about half a block from the bank, Ruth said.

But before he got in, witnesses said he opened the bag of money, and a dye pack exploded on his head and shoulders, Ruth said. Officers later found the bag, with the cash still inside.

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Police searched the neighborhood with canines, but did not find the suspect, Ruth said.

The robber is described as a 5-foot-7 to 5-foot-8 white man wearing a gray hooded sweatshirt and gym shoes, according to the FBI.

Lincoln Elementary School, Bryan Middle School, Madison Early Childhood School and Jackson Elementary School were all put on a soft lockdown for about an hour during the search, Ruth said.

No one was in custody as of late Wednesday afternoon. Anyone with information should call the FBI at (312) 421-6700.

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(Source: Sun-Times Media Wire © Chicago Sun-Times 2014. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)