CHICAGO (CBS) — An Amazon delivery truck was stolen Thursday morning in the Bridgeport neighborhood.

Police said the driver was returning to his truck after making a delivery on the 3100 block of South Normal Avenue around 8 a.m., when an armed man approached and demanded the keys to the truck.

READ MORE: Police Warn Of Retail Thefts in Gold Coast

The driver gave the robber the keys, and the suspect got in the truck and drove away, according to police.

The driver was not injured.

READ MORE: Police Surround Apartment Of Barricaded Subject In Villa Park

Area Central detectives were investigating.

The robbery follows a string of hold-ups targeting delivery drivers in Chicago in recent weeks. Robbers targeted at least seven package delivery trucks in Chicago in December, including FedEx trucks and UPS trucks. In some cases, the robbers stole the trucks themselves, and in other cases stole packages out of the trucks.

MORE NEWS: Missing Bensenville Dog Reunited With Owners

Earlier this week, two U.S. Postal Service carriers were robbed on the South Side. On Wednesday, two men stole a mail carrier’s property at gunpoint in the Roseland neighborhood. On Tuesday, a gunman stole a large quantity of mail and a package from a Postal Service truck in the South Shore neighborhood, after threatening the mail carrier with a gun.