Banks are where the money is, and they are also where people go to put money in and get it out. All three functions of banks led to robberies this month in the Washington region.

In the Manassas area of Prince William County, police said, a man cashed a check at a BB&T branch on Sudley Road about noon Sept. 16. He had just left the bank when a robber came up from behind and knocked him down. The robber took a backpack containing currency and fled, police said.

On the same day, in the Germantown area of Montgomery County, a fast-food restaurant employee was taking receipts to a PNC branch on Middlebrook Road about 9:50 a.m., police said.

As she walked up to the entrance, police said, a robber grabbed her, pulled her down and took the bag of money. He got into a car, which drove off, police said.

One of the most recent robberies of a bank, rather than a customer, occurred about 3 p.m. Friday at the Baltimore County Savings Bank branch on Eastern Boulevard in the Essex area of the county.

Two robbers passed a note to a teller implying that they had a bomb, Baltimore County police said.

The robbers got money and fled in a vehicle. The vehicle was stopped not far away, and three women were arrested, the police said.