FREDERICK COUNTY, Md. (WDVM) — Montgomery County police are investigating a bank robbery that occurred on Tuesday in Gaithersburg.

Police say the suspect entered an M&T Bank on the 18000 block of Flower Hill Way around 10:30 a.m. where he approached a bank teller.

Authorities reported he asked for account information to be looked up, the teller asked for identification, he said he didn’t have it with him. After a brief exchange of words, the suspect claimed that he would come back soon.

According to Montgomery County police, the suspect came back around 11:45 a.m. and demanded the teller put money in a plastic bag while showing her he had a gun.

The teller put the money in the bag, along with the money he demanded from another teller.

Police said that as the suspect was leaving the location, the dye pack exploded.

A dye pack is made out of a stack of bills, typically ten or twenty dollars, with a dye device inserted in the middle, causing stolen cash to be permanently marked with dye.

Police say, the suspect is described as possibly White or Hispanic, approximately 5-feet, 10-inches tall, 200 lbs., wearing jeans, a black jacket or hoodie, green and tan camo neck gaiter as a mask, a black beanie cap and black gloves and armed with a black handgun.

To give information, contact the Montgomery County Police Major Crimes Division at 240-773-5070.